I have the same model, and it was doing the same thing, when it was cold outside,. Nobody could figure it out! Then I thought heck I pull the cap and rotor off. I found the problem!!!!! The was really carbon up and the metal was bent and twisted. (I put the cap & rotor on 6 mo earlier, so I didn't think that would be the problem but it was! The store sold me a piece of junk, made in Japan. I put on a AC-Delco cap and rotor, no more problems! Car can sit a week in freezing and still start with tap of the key!!!!
I work for a Ford dealer here in the UK, (but haven't been in the workshop for nearly 20 years) Ford are now using MAF and MAP sensors on the same system to verify EGR flow. Depending on the managment system employed, either sensor is used for primary airflow measurement, while the other is for EGR flow verification.
Eric,great videos,fellow mechanic here,on the use of the MAP sensor with MAF Systems,its pretty much there as a failsafe,Fuel control with older (Pre-MAF) systems is called speed density,it used RPM,MAP and TPS Readings compared to a programmed fuel/timing table to make adjustments,on newer systems,if the MAF fails it will run like crap breifly or stall,but on restart the computer catches the failure,turns on the check engine light and uses the MAP sensor system/Limp Mode and seems to run ok.
Ahh yes, that engine brings back fond memories of my 2000 Jimmy when I had to replace the intake manifold gasket 2 years ago. The gaskets on those were notorious for leaks. My cooling system kept gettimg reoccurring brown crud just like in this video and Scotty Kilmer said it's a sign of a future head gasket failure. That's 1 of 2 reasons I got rid of it and the other is because at 20 mpg I was filling the tank about every 4 days.
Eric - Had this symptom and found the fix, hope your is the same. Next cold morning have the owner plug I the block heater for an hour prior and if the truck starts right up you know the coolant temp signal to ecm is faulty and its just a new sensor. Engine was trying to start on a warm temp signal and not enough fuel . Worked for me.
Worked on ton of these...check those intake gaskets if the coolant is low, they were just as bad as GM's 3.4/3.1 intake gaskets. The system was changed in '96 to a CSFI (Central Sequential Fuel Injection)system which was a good improvement over the previous CMPI (Central Multi Port Injection). They are finicky when it came to fuel pressure, it had to be very accurate or you would have all sorts of drivability/non start/cold start issues. Aftermarket fuel pumps caused issues all the time...
I have the exact same problem with my 01 s10 as post below. Starts great when really cold but not when warm or if I've used block heater. Excellent video! I learned a lot.
Eric!!! I got all excited when I saw you were going to dig into a GM 4.3l Jimmy/Blazer/Sonoma/S10, and then no repair ... bummer! I know they are not a Honda, but there must be well over 100,000 of these GM 4.3l and 2.2l vehicles still on the road/ Looking forward to your Sonoma engine video, Thanks for publishing some great work on RUclips, as usual it's informative and never cheesy. I appreciate that you know what audience you want to attract. Charlie
Fuel pump; these require 50 to 60 psi to start and run correctly. Check the fuel pressure after it has been sitting with the key on then at startup and while running. Very common cause of the hard start is after the engine has sat and is cold, the fuel pressure will leak back down through the faulty fuel pump causing a long crank time if it will even start at all.
I'm wondering if that might be the problem that I'm experiencing. The symptom is that after the truck has sat for a day, it is difficult to start. I have noticed that I can try to start it by turning the key several times and usually it won't start. However, if I wait for a minute or so and try again usually it will start. I've been wondering if maybe fuel or antifreeze or something is leaking into the cylinders and causing a problem. Anyone have any ideas as to why letting it sit there for a minute would help? I need to get an OBDII scanner to check it. At one point the check engine light came on, but, then turned off after running it for awhile.
I should add that the fuel gauge has been broken for awhile. Which I think you have to change the fuel pump to fix that. I haven't done it though since I am not looking forward to having to drop the tank, etc.
I've the misfortune of working on a few of the motors. I actually do love the motors. They run a long time if maintained properly (oil changes, coolant changes) but with this style intake, GM incorporated a few well known problems. The back left corner, driver side, is known to spring a major coolant leak there. Its just a weak point of the intake. The old spider injection lines were known to crack and leak fuel into the motor. With the condition of the inside of that radiator, I would dare to guess the intake was leaking coolant. I just wish GM and all vehicle manufacturers would have left the intakes aluminum and used aluminum instead of plastic molding for the gaskets. Just like the GM 3.8 series 2 engines, i absolutely love them, except the plastic upper intake and valve covers. If you can find them I STRONGLY suggest converting the intake to aluminum, hard to find but well worth the search and $$. I changed mine from plastic to aluminum on my 01 Grand Prix, 236,000 miles, no problems.
I had a 2002 S10 Eric with the exact same engine. Never had any problems with the injection system (GM called it Central Sequential Injection, one centrally located injector feeding 6 tubes thru poppet nozzles ) Terrible design in my opinion. I believe they offer a multi port injection conversion for these systems. Love the videos, keep 'em coming
Thank you so much for this video! I have been fighting a hard start issue with my 2002 S10 4.3 for the last year or so. Will try the steps you showed...
hey car guy, ive stumbled on this looking for cold start circuit issues on same truck , blown fuse not the case here but seen it a few times on others, ive been rebuilding alternators and starters, since i was 12, with dad of course,nearly 50 years now !
GM has actually changed the design of these spider injectors because they had so many problems. instead of having just one central injector that goes out to the spider legs it gets converted to essentially multiport fuel injection by using 6 injectors and a "leg" for each clinder.
Great tip with checking the ECM even if the engine light is not on. My brother purchased a used RSX from someone that removed the LED for the check engine light. I would never know anything was ever wrong if I hadn't hooked up my scan gauge to it. Yup! Had an an EDL code and various other issues.
That intake tube directly over the throttle body should have a metal clip that holds itself to the throttle body. That and the plastic wing nut extension holds down the intake tube to throttle
I've seen both MAP and MAF sensors used on some vehicles. I always heard that the MAP is not used primarily for fuel adjustments but it is used as a backup for the MAF in case there is a malfunction. Also I think it also assists in doing diagnostic checks on the MAF to make sure that that it is indicating the proper density of air.
@14.00 what Eric is referring to is the central port injection system these late 90-early 2000 4.3s always had. "Spider" is just this systems nickname. This component was basically one big fuel injector with six leads that go to individual poppets to inject fuel into the intake. They were known for failing, and unfortunately, are very expensive to replace.
I think I read somewhere online, engines that have a MAF and MAP sensor (GM vehicles in particular) will generally only use the MAP sensor to verify operation of the EGR valve. The computer will be able to see a change in manifold pressure when it opens/closes the EGR valve.
GM was on the mark when they discontinued the S10/Sonoma and introduced the Colorado/Canyon! I used to own a Sonoma and now I own a Colorado. Never go back!
Hi Eric, 99 gmc safari van 4.3 v6 has opposite issue. Engine starts perfect when cold but Cranks forever when hot. Eventually it starts and stalls ...immediately crank again and it starts and runs ruff for 2 seconds...Then seems to run fine. Fuel pressure tests fine at 60 pounds however it begins to bleed down right away possibly a bad fuel pressure regulator in the Plenum. Spark plugs wires rotor all change with AC Delco new parts makes no difference. Vacuum seems fine as the HVAC controls are vacuum operated and they are working fine. Changed out a bad coolant temperature sensor now the temp Reaches 210 normally. Normally no check engine lights however after the long hot start and stall ...I sometimes get a PO302 misfire detected cylinder 2 ...sometimes ...I get no check engine light all the pens how hard the stall is. I’m leaning towards a leaky fuel pressure Regulator located inside the intake Plenum but I’m not sure why it starts perfectly fine when the engine Has been sitting for 8+ hours. I hate to take the whole intake Plenum apart as it’s a big job to change out a $20 part. All fluid levels are perfect. Ignition coil in regulator have been changed out , no difference. Any thoughts or suggestions?
Eric, U R working on an American vehicle. O M G !!!!! O M G!!!!! I thought I was seeing things. Have been buying GMC and Chevorlet Trucks for 43 years. Most likely put a million miles or more in total on them. All they ever did was run. Never had a majior break down, and 4 the most part I have hauled trailers and tree trunk legnth trees for fire wood. Ford is crapol'a to me. My 06 Silverado has 250 thousand miles on and runs perfect. Amen.
Mine is like that on the s10 and I have a similar cold start problem. Gonna try replacing that and cleaning the MAF. So ready to sell this for better mileage. As a mini truck owner, I regret not getting a v8. 15-20 mpg for 190 horse is sad
Also the throttle body rubber seal is missing on the top. Eric is correct, their should be an orange rubber seal there. Which would help with the vacuum leaks.
I changed from the stock sfi to the mfi spider system on my 96 jimmy. I've put about 10k miles on it and no problems so far. Also, you can buy individual injectors for it.
2003 removed the poppet valves from the spider injector system. What’s real common to do is when the engine starts having injectors fail, is to convert from the pre 03 system, to the 03+ system. It’s also recommended when to do it when the LIM fails (which it will. They all will fail) and needs to be replaced since you’re right there.
If ya have a 4.3 Vortex Engine? It's your Camshaft Position Sensor. This is for Cold & Warm hard Starting. I had the issue & couldn't figure it out until the it threw the code.
Eric I have a 96 chevy blazer 4.3 engine I just wanted to say this the new MPFI spyders are more reliable than the original poppet CPI spyders were and that top of the air intake cover is missing the metal hold down bracket. One last thing love the videos man thank you.
Hey Eric I to have a 95 gmc jimmy 4.3lv6 It needs a lot of love When my Engine is running an in park sitting in my driveway there is this black stuff that spits out the exhaust tail pipe. As well as I can smell fuel . An when I’m string in drive with my foot on the Break my truck runs ruff an shaking But runs fine going down the road. One thing I did do is cool air intake filter with stock intake flex tubing . I wanna go back oem intake I just put a new tps sensor map sensor ideal air control sensor I put in a new fuel pressure regulator. But I think I need a new oem spider injector Assembly kit. It’s got new plugs an wires cap an rotor timing positioning sensor. My Electric motor for 4 wheel drive doesn’t work An it needs a new actuator switch for front diff. But no check engine light plus it’s an obd1 An it’s got a big AC leak I live in the desert we’re I live it gets to be like 116 to 120 in the summer. I pick this truck up for $1300 I mean it’s came a long way from the way it use to run when first bout it . But it’s got a long way to go still. But at least I don’t got a car payment. Some day I’ll get everything fixed just a little at a time. But I like the soapy wooder trick you did for checking for vacuum leaks. If you get the opportunity on some more gmc jimmy jobs. Much a presented not much out there on these trucks there cool look in trucks .
Another thing that can cause hard or no start in freezing conditions is having no drain in the muffler. Happened to a buddy of mine who had an aftermarket exhaust put on his truck in the summer, then in the winter would never start on really cold mornings. 2 winters and 6 garages later an old timer mechanic laughed when he heard the problem and drilled a small hole in his muffler. has not had a problem since..
Watching this video makes me never want to take my car to the shop because these "technicians" often misdiagnose these simple problems and make you buy all these expensive parts the car doesen't need. I'm with you on the faulty regulator-it could have a leaky injector also. I took my car to the dealer once and instead of pinpointing the problem,they wanted to just throw parts at it until it was fixed. I declined and they still charged me $125 just for pulling into the shop.
The old 1st generation fuel spiders are known to fail on that engine. It killed off my S10 at 265000 miles. It had the same problem as this one does, first being hard to start in the cold and eventually not starting at all. They aren't very easy to replace
Eric if you have a android phone, get a basic ELM327 OBD-II device and get torque from the play store. You will have access to pretty much very sensors output, you can log them, Most ELM327s have a do about 15PID per second. and it does to the check codes too.
my grandpa took his cadilac into the mechanics one day because the starter wasnt engaging every time and he said"im too old and fat to get under there nowadays" the mechanic turned the key,and every single time,the starter engaged and started the engine. it took the mechanic 3 days to get the starter to not engage when he turned the key.
Dexcool, did eat the first engine gaskets that came with Dexcool, but GM and Felpro have updated their gaskets to be compatible with Dexcool and the acid EH-2 that is in the coolant. FYI new world order almost all Fords now come from the factory with a Dexcool type coolant in them as, and several CDJR also use a DEX type coolant
The mighty 4.3! The vaccum leak is probably the o-ring that seals the spider to the plenum but you would run into trouble removing it with your gluey situation. As far as the coolant leak I would say intake manifold gasket, if there is coolant sitting on the back side. I wouldn't fuss too much about bleeding it, just leave the cap off for a couple minutes while running and your golden....they pretty much bleed themselves.
i just rebuilt the 4.3 in my friends 98 blazer. could be an intermittent knock or crank sensor, vacuum or evap leak. bad intake manifold gaskets, bad O rings for upper intake or fuel lines. spider injectors are known to fail in these engines. Low Coolant.The loose air intake to throttle body is common. I did the timing on his blazer and the thing starts right away no hesitation. timing might need to be adjusted. From your certified Diesel Technician and Auto Hobbyist.
Problems with the spider, and the poppet injectors are common, and so are intake gaskets going bad and the motor sucking in coolant. But that's just what I've heard, there's been plenty of these 4.3's in S10's and full size trucks in my family over the years, and never a problem. I don't understand why people claim to have so many problems, and always say they're junk.
There is a really nice case study on CPI injection with scannerdanner, that to me is a fuel pump on his way out , i want to say when is cold, battery gets a little weaker and fuel pump wont make the psi required , those CPI are very finicky aparently, if you dont have the exact psi required it will never start,i bet that truck will soon will get hard to start even in hot weather,you found a vaccum leak but i think thats a different problem,have them jumpstartit whe they have the problem.
Thatis the Vortec spider system. All the injectors are hidden inside the manifold plenum. I have the earlier version of the same system in my '93 Sonoma. Works well. Earlier CPI systems have an all aluminum manifold with the throttle body mounted on the front of the plenum facing the fan. Newer systems have the throttle body mounted on top of the plenum.
Eric, i used to own a 97 of the same vehicle and my intake above the throttle body had the same little screw to hold it down and it had a big clamp around the base to secure seal to the throttle body.
Crusty radiator and oil cap is typical of all of my well maintained 4.3s. These run 200,000 plus easy if maintained. I have owned and driven 6-8 high mileage units over the last 15 yrs or so. Most have lost coolant but I keep everything cked and filled.
You can get a cigarette or cigar and pull of a vacuum hose and blow smoke in it and where smoke comes out at is a vacuum leak. It works for me and makes it easier to find leaks.
Where the intake elbow mounts to the throttle body there should be a metal clip that helps hold the intake elbow down onto the throttle body and the wing nut holds it down on the rear.
Delphi or AC Delco MPFI conversion spider is the only way to go. This updated part includes the regulator. Not sure if the plastic fuel lines inside the intake are included, but they should all be replaced at the same time.
My first car was a Honda Civic and it was constantly having issues. was a 2001 and my sister owns a 2002 and its about to crap out on her too. thats why I got rid of it and got a 2006 chevy cobalt. never had one single issue with it so far. props to american cars.
I'm having an issue along the lines of this. It's a 2002 Chevy 2500HD with the 6.0 Vorteck with a throttle cable. Not electric throttle. . On days when it's below 25 degrees. When I start it. It starts right up. The rpm kicks up to 1000 like normal but after 5 seconds the rpm drops to the point where it barley is running. It's sputters at a very low rpm for around 30 seconds and then picks back up to 1000 rpm. Then several seconds later it will drop back down and barley run. It will either stall out or continue this until the engine temp picks up a bit. After that it runs perfect. On warmer days it starts right up and runs perfect. It runs very well and doesn't burn oil. I don't think it's fuel related as it has new fuel pump, filter and lines. It did this before and after the new pump. It idles normally when it's not doing this. Plus It's been doing this for as long as I can remember. My father got this truck in 2003 and it's now mine after he bought a new truck. It's done this ever since he's gotten it. I'm stumped and can't find a solution, any suggestions.
I have the same exact problem when it gets cold. I went through the whole ordeal of checking fuel pressure, all good. Turns out it's the cheap ass plastic wheel on the ignition key module that gets stiff when it gets cold. I've learned to simply turn the key switch very slowly until I feel the spring tension and then crank-it starts every time without having to tear out the column and replace it with an even worse chinese aftermarket POS.
Hmm, never had starting issues with my Explorer, never had rusty coolant. But then again I actually take care of my vehicles and perform regular maintenance.
I know this video is old, but I drive an '02 Blazer and there is supposed to be a metal clip that holds that resonator tight to the front end of the throttle. The clip is missing on this one.
Every time I have a problem like this it's either a temp sensor (I.A.T. or coolant) or it's a vehicle that's never seen a tuneup EVER. I've never worked on one of those though, as I've been warned to stay as far away from the spider injection systems as possible.
the oring that sits around the top of that plug is a known issue with those! both my 98 and my 03 GMC had it and as for spider the earlier spider you can rebuild! I have a mfi spider that I had in my 98 but couldn't find pophet for it so I got a junk yard one from a 01 and replaced all the legs and seals and works perfect! my 03 has the mfi as where my 98 has cfi and I couldn't tell a real difference
I have Gmc Sonoma 2000 know it starts some days and not other it ran all summer no problem. My thoughts was wire's has not Ben change since the purchase of vehicle. I'll check for leakage.
one way too check for vacum leak,indentify fuel trims are high at idle.Then raise rpm,s-if fuel trims start going back too normal you have a vacum leak.Also + 5.4 on bank 2 ftft I wouldnt say is excessive.Rule of thumb is if its under 5% its ok...good luck
Are you looking to buy new or used? Basically anything that is slow is a good car as a first car. If you are looking for new and fuel efficient I would say a Fiesta or a Focus but I am a Ford fan, but it could easily be a Chevy Sonic. There really is a lot to choose from depending on budget.
I have a 2000 Blazer and am hoping to see you replace the spider injector assy. I was told that if you remove the throttle body and look into the upper part of the intake and see fuel (wet) that is an indication of a failing spider. Also random misfires and that is what mine is doing now. I read also that the spider was redesigned and that the new style has 6 individual injectors instead of one multi injector unit. It is a direct replacement.
those are wonderfuel(sarcasm), i've done dozens in my gm days, used aftermarket a few times in a pinch, never any real issues, but mostly used O.E parts since it was a stealership, also fuel prime MUST be at min 59psi or hard cold start occurs(it'll run on 52, so don't let that fool you thinking no fuel delivery problem)
I have 1999 GMC Jimmy with 4.3. Never had a problem with it starting cold until we just replaced the fuel pump. Does this have a cold start valve? It runs fine on warm days, and I have to jump on cold days cause it drains battery. What do I look for to fix problem?
Hi ETCG. That could be the crankshaft position sensor failing. I have a totally different car, but the basic concept is the same. Mine was acting up in cold mornings but not in hot weather. The starter would turn the engine without a problem, but the injection computer didn't know the engine was turning, so it didn't inject fuel. Now, sensor replaced, and the engine always starts :) Hope you can find the problem.
I had a similar problem. Car died all of a sudden and then would refuse to start. It turned out to be the fuel pump connectors that somehow seemed to work themselves loose. Of course my engine is has near as makes no difference 500k km and has a myriad of electrical gremlins. But that GM LHO 3.1 V6 sure is a tank it just keeps on chugging along and breaking down occasionally usually due to wiring issues or sensor failures.
I don't know, I just always thought than if you take your car to somebody you trust, that you'd have secured the ability to pay for up to what the vehicle's value warrants. This guy lost the diag fee and by the time they are of the means to deal with the problem things will likely have gotten worse.The best thing that could happen now is that it progresses to where it fails smogcheck and either fix it right or junk it.
I've never been to nor heard of a shop that don't charge for diagnostics. If he let the customer walk without paying it's on him or the shop he works for.
I'm thinking about moving up to a truck from a car. Would like a Diesel, but they're too expensive. Seen one of these on CL. A 2001 w/ 145k miles. Any thoughts on Sonomas? I'd say I'm pretty mechanically inclined, do all my own maintenance. I kind of know what to look for on a used gas engine. Leaks, dirty filters, low fluids etc. I just don't want to waste time checking it out if it isn't worth it. I haven't really seen to many of these on the road.
I have a 95 Chevy 3500 with a 454... when I go to start it when the engine is cold, it fires right up but I have to feather the throttle to keep it running, it tries to load up with gas and occasionally will backfire through the exhaust, this happens only for about a minute then it clears up and the truck runs perfect.... it only does this at the initial start when the engine is cold, if it has any engine heat it starts and runs perfect. Any help is appreciated.
I have the same model, and it was doing the same thing, when it was cold outside,. Nobody could figure it out! Then I thought heck I pull the cap and rotor off. I found the problem!!!!! The was really carbon up and the metal was bent and twisted. (I put the cap & rotor on 6 mo earlier, so I didn't think that would be the problem but it was! The store sold me a piece of junk, made in Japan. I put on a AC-Delco cap and rotor, no more problems! Car can sit a week in freezing and still start with tap of the key!!!!
I work for a Ford dealer here in the UK, (but haven't been in the workshop for nearly 20 years) Ford are now using MAF and MAP sensors on the same system to verify EGR flow. Depending on the managment system employed, either sensor is used for primary airflow measurement, while the other is for EGR flow verification.
Eric,great videos,fellow mechanic here,on the use of the MAP sensor with MAF Systems,its pretty much there as a failsafe,Fuel control with older (Pre-MAF) systems is called speed density,it used RPM,MAP and TPS Readings compared to a programmed fuel/timing table to make adjustments,on newer systems,if the MAF fails it will run like crap breifly or stall,but on restart the computer catches the failure,turns on the check engine light and uses the MAP sensor system/Limp Mode and seems to run ok.
Ahh yes, that engine brings back fond memories of my 2000 Jimmy when I had to replace the intake manifold gasket 2 years ago. The gaskets on those were notorious for leaks. My cooling system kept gettimg reoccurring brown crud just like in this video and Scotty Kilmer said it's a sign of a future head gasket failure. That's 1 of 2 reasons I got rid of it and the other is because at 20 mpg I was filling the tank about every 4 days.
I 4
Eric - Had this symptom and found the fix, hope your is the same. Next cold morning have the owner plug I the block heater for an hour prior and if the truck starts right up you know the coolant temp signal to ecm is faulty and its just a new sensor. Engine was trying to start on a warm temp signal and not enough fuel . Worked for me.
Worked on ton of these...check those intake gaskets if the coolant is low, they were just as bad as GM's 3.4/3.1 intake gaskets. The system was changed in '96 to a CSFI (Central Sequential Fuel Injection)system which was a good improvement over the previous CMPI (Central Multi Port Injection). They are finicky when it came to fuel pressure, it had to be very accurate or you would have all sorts of drivability/non start/cold start issues. Aftermarket fuel pumps caused issues all the time...
I have the exact same problem with my 01 s10 as post below. Starts great when really cold but not when warm or if I've used block heater.
Excellent video! I learned a lot.
Eric!!! I got all excited when I saw you were going to dig into a GM 4.3l Jimmy/Blazer/Sonoma/S10, and then no repair ... bummer! I know they are not a Honda, but there must be well over 100,000 of these GM 4.3l and 2.2l vehicles still on the road/ Looking forward to your Sonoma engine video, Thanks for publishing some great work on RUclips, as usual it's informative and never cheesy. I appreciate that you know what audience you want to attract.
Charlie
Fuel pump; these require 50 to 60 psi to start and run correctly. Check the fuel pressure after it has been sitting with the key on then at startup and while running. Very common cause of the hard start is after the engine has sat and is cold, the fuel pressure will leak back down through the faulty fuel pump causing a long crank time if it will even start at all.
I'm wondering if that might be the problem that I'm experiencing. The symptom is that after the truck has sat for a day, it is difficult to start. I have noticed that I can try to start it by turning the key several times and usually it won't start. However, if I wait for a minute or so and try again usually it will start. I've been wondering if maybe fuel or antifreeze or something is leaking into the cylinders and causing a problem. Anyone have any ideas as to why letting it sit there for a minute would help? I need to get an OBDII scanner to check it. At one point the check engine light came on, but, then turned off after running it for awhile.
I should add that the fuel gauge has been broken for awhile. Which I think you have to change the fuel pump to fix that. I haven't done it though since I am not looking forward to having to drop the tank, etc.
@@idmhead0160 I'd get a fuel pressure gauge before scanner. Sounds like a bad fuel pump if the fuel level gauge isn't working.
Great video! My 03 Jimmy is sometimes having a hard start. The times it's happened is after it's been running for a while.
I've the misfortune of working on a few of the motors. I actually do love the motors. They run a long time if maintained properly (oil changes, coolant changes) but with this style intake, GM incorporated a few well known problems. The back left corner, driver side, is known to spring a major coolant leak there. Its just a weak point of the intake. The old spider injection lines were known to crack and leak fuel into the motor. With the condition of the inside of that radiator, I would dare to guess the intake was leaking coolant. I just wish GM and all vehicle manufacturers would have left the intakes aluminum and used aluminum instead of plastic molding for the gaskets. Just like the GM 3.8 series 2 engines, i absolutely love them, except the plastic upper intake and valve covers. If you can find them I STRONGLY suggest converting the intake to aluminum, hard to find but well worth the search and $$. I changed mine from plastic to aluminum on my 01 Grand Prix, 236,000 miles, no problems.
the starter motor uses coolant?! or are you talking about the engine
rasvial engine
I had a 2002 S10 Eric with the exact same engine. Never had any problems with the injection system (GM called it Central Sequential Injection, one centrally located injector feeding 6 tubes thru poppet nozzles ) Terrible design in my opinion. I believe they offer a multi port injection conversion for these systems. Love the videos, keep 'em coming
Thank you so much for this video! I have been fighting a hard start issue with my 2002 S10 4.3 for the last year or so. Will try the steps you showed...
hey car guy, ive stumbled on this looking for cold start circuit issues on same truck , blown fuse not the case here but seen it a few times on others, ive been rebuilding alternators and starters, since i was 12, with dad of course,nearly 50 years now !
Nice job hooking up the pcv hose to the back of the throttle body. That's why the idle was rough.
GM has actually changed the design of these spider injectors because they had so many problems. instead of having just one central injector that goes out to the spider legs it gets converted to essentially multiport fuel injection by using 6 injectors and a "leg" for each clinder.
Great tip with checking the ECM even if the engine light is not on. My brother purchased a used RSX from someone that removed the LED for the check engine light. I would never know anything was ever wrong if I hadn't hooked up my scan gauge to it. Yup! Had an an EDL code and various other issues.
That intake tube directly over the throttle body should have a metal clip that holds itself to the throttle body. That and the plastic wing nut extension holds down the intake tube to throttle
Timing is more advanced during cold start up. It goes to normal after it goes into closed loop.
Thanks Eric, I liked when you named all these elements beginning from inlet for the idle in the throttle body.
Thanks Eric. Learned something about fuel trim today. Just got my own actron cp9580 and it works well.
So what was the problem again?
I've seen both MAP and MAF sensors used on some vehicles. I always heard that the MAP is not used primarily for fuel adjustments but it is used as a backup for the MAF in case there is a malfunction. Also I think it also assists in doing diagnostic checks on the MAF to make sure that that it is indicating the proper density of air.
There is a seal on that intake where it attaches to the throttle body. I have a Silverado with the same engine and it has one.
@14.00 what Eric is referring to is the central port injection system these late 90-early 2000 4.3s always had. "Spider" is just this systems nickname. This component was basically one big fuel injector with six leads that go to individual poppets to inject fuel into the intake. They were known for failing, and unfortunately, are very expensive to replace.
The SFT and LFT ARE taken from the O2 readings, it's like a summary of their operation.
I think I read somewhere online, engines that have a MAF and MAP sensor (GM vehicles in particular) will generally only use the MAP sensor to verify operation of the EGR valve. The computer will be able to see a change in manifold pressure when it opens/closes the EGR valve.
GM was on the mark when they discontinued the S10/Sonoma and introduced the Colorado/Canyon! I used to own a Sonoma and now I own a Colorado. Never go back!
Hi Eric, 99 gmc safari van 4.3 v6 has opposite issue. Engine starts perfect when cold but Cranks forever when hot. Eventually it starts and stalls ...immediately crank again and it starts and runs ruff for 2 seconds...Then seems to run fine. Fuel pressure tests fine at 60 pounds however it begins to bleed down right away possibly a bad fuel pressure regulator in the Plenum. Spark plugs wires rotor all change with AC Delco new parts makes no difference. Vacuum seems fine as the HVAC controls are vacuum operated and they are working fine. Changed out a bad coolant temperature sensor now the temp Reaches 210 normally. Normally no check engine lights however after the long hot start and stall ...I sometimes get a PO302 misfire detected cylinder 2 ...sometimes ...I get no check engine light all the pens how hard the stall is. I’m leaning towards a leaky fuel pressure Regulator located inside the intake Plenum but I’m not sure why it starts perfectly fine when the engine Has been sitting for 8+ hours. I hate to take the whole intake Plenum apart as it’s a big job to change out a $20 part. All fluid levels are perfect. Ignition coil in regulator have been changed out , no difference.
Any thoughts or suggestions?
the vortex 4.3 liter 6 composition chambers is as all gms engines one of the best car engine man has ever made .
Eric, U R working on an American vehicle. O M G !!!!! O M G!!!!! I thought I was seeing things. Have been buying GMC and Chevorlet Trucks for 43 years. Most likely put a million miles or more in total on them. All they ever did was run. Never had a majior break down, and 4 the most part I have hauled trailers and tree trunk legnth trees for fire wood. Ford is crapol'a to me. My 06 Silverado has 250 thousand miles on and runs perfect. Amen.
I did a service on a GMC truck here in the UK once, the brake shoes were twice the size of a normal car here! It was crazy
I notice that the duct that bolts on to the throttle body is missing the clip on the front of it that helps hold it down.
Mine is like that on the s10 and I have a similar cold start problem. Gonna try replacing that and cleaning the MAF. So ready to sell this for better mileage. As a mini truck owner, I regret not getting a v8. 15-20 mpg for 190 horse is sad
Also the throttle body rubber seal is missing on the top. Eric is correct, their should be an orange rubber seal there. Which would help with the vacuum leaks.
Man for a higher mileage Jimmy that this is really clean. Not often do I see the Jimmy or S10 blazer in any kind of well kept condition.
I changed from the stock sfi to the mfi spider system on my 96 jimmy. I've put about 10k miles on it and no problems so far. Also, you can buy individual injectors for it.
That particular GMC V6 and V8 spider fuel injector asembly is a piece of crap of engineering, thanks for your videos!
Gaaaarrrebbaaaaaagggeeee
2003 removed the poppet valves from the spider injector system. What’s real common to do is when the engine starts having injectors fail, is to convert from the pre 03 system, to the 03+ system. It’s also recommended when to do it when the LIM fails (which it will. They all will fail) and needs to be replaced since you’re right there.
If ya have a 4.3 Vortex Engine?
It's your Camshaft Position Sensor. This is for Cold & Warm hard Starting. I had the issue & couldn't figure it out until the it threw the code.
Eric I have a 96 chevy blazer 4.3 engine I just wanted to say this the new MPFI spyders are more reliable than the original poppet CPI spyders were and that top of the air intake cover is missing the metal hold down bracket. One last thing love the videos man thank you.
Think I see the problem. Somebody sprayed soapy water all over under there.
fungoorstitch all under where?
Hey Eric
I to have a 95 gmc jimmy 4.3lv6
It needs a lot of love
When my Engine is running an in park sitting in my driveway there is this black stuff that spits out the exhaust tail pipe.
As well as I can smell fuel . An when I’m string in drive with my foot on the Break my truck runs ruff an shaking
But runs fine going down the road. One thing I did do is cool air intake filter with stock intake flex tubing . I wanna go back oem intake
I just put a new tps sensor map sensor ideal air control sensor I put in a new fuel pressure regulator. But I think I need a new oem spider injector Assembly kit.
It’s got new plugs an wires cap an rotor timing positioning sensor.
My Electric motor for 4 wheel drive doesn’t work
An it needs a new actuator switch for front diff. But no check engine light plus it’s an obd1
An it’s got a big AC leak
I live in the desert we’re I live it gets to be like 116 to 120 in the summer.
I pick this truck up for $1300 I mean it’s came a long way from the way it use to run when first bout it . But it’s got a long way to go still. But at least I don’t got a car payment. Some day I’ll get everything fixed just a little at a time. But I like the soapy wooder trick you did for checking for vacuum leaks. If you get the opportunity on some more gmc jimmy jobs. Much a presented not much out there on these trucks there cool look in trucks .
Another thing that can cause hard or no start in freezing conditions is having no drain in the muffler. Happened to a buddy of mine who had an aftermarket exhaust put on his truck in the summer, then in the winter would never start on really cold mornings. 2 winters and 6 garages later an old timer mechanic laughed when he heard the problem and drilled a small hole in his muffler. has not had a problem since..
Watching this video makes me never want to take my car to the shop because these "technicians" often misdiagnose these simple problems and make you buy all these expensive parts the car doesen't need. I'm with you on the faulty regulator-it could have a leaky injector also. I took my car to the dealer once and instead of pinpointing the problem,they wanted to just throw parts at it until it was fixed. I declined and they still charged me $125 just for pulling into the shop.
Has Eric ever responded to questions?
The old 1st generation fuel spiders are known to fail on that engine. It killed off my S10 at 265000 miles. It had the same problem as this one does, first being hard to start in the cold and eventually not starting at all. They aren't very easy to replace
gotta love it when people dont want to take care of stuff or fix know problems then they are stuck on the side of the road
There also is a o ring that goes around the portion where you the electrical connections and fuel lines that would need to be checked.
it's not what you drive it's how you take care of it. Treat your car well and it treats you well
Eric if you have a android phone, get a basic ELM327 OBD-II device and get torque from the play store.
You will have access to pretty much very sensors output, you can log them,
Most ELM327s have a do about 15PID per second. and it does to the check codes too.
my grandpa took his cadilac into the mechanics one day because the starter wasnt engaging every time and he said"im too old and fat to get under there nowadays" the mechanic turned the key,and every single time,the starter engaged and started the engine. it took the mechanic 3 days to get the starter to not engage when he turned the key.
Dexcool, did eat the first engine gaskets that came with Dexcool, but GM and Felpro have updated their gaskets to be compatible with Dexcool and the acid EH-2 that is in the coolant.
FYI new world order almost all Fords now come from the factory with a Dexcool type coolant in them as, and several CDJR also use a DEX type coolant
The mighty 4.3! The vaccum leak is probably the o-ring that seals the spider to the plenum but you would run into trouble removing it with your gluey situation. As far as the coolant leak I would say intake manifold gasket, if there is coolant sitting on the back side. I wouldn't fuss too much about bleeding it, just leave the cap off for a couple minutes while running and your golden....they pretty much bleed themselves.
These 4.3 engines are Great 433k miles with only 1 Spyder injection changed out Still runs like a Rock
I'm afraid I might have that issue with mine. 311k miles currently.
i just rebuilt the 4.3 in my friends 98 blazer. could be an intermittent knock or crank sensor, vacuum or evap leak. bad intake manifold gaskets, bad O rings for upper intake or fuel lines. spider injectors are known to fail in these engines. Low Coolant.The loose air intake to throttle body is common. I did the timing on his blazer and the thing starts right away no hesitation. timing might need to be adjusted. From your certified Diesel Technician and Auto Hobbyist.
i own an 02 chevy blazer. what a great truck! They sure have some stupid little problems, but these are fantastic trucks with tank engines!
Problems with the spider, and the poppet injectors are common, and so are intake gaskets going bad and the motor sucking in coolant. But that's just what I've heard, there's been plenty of these 4.3's in S10's and full size trucks in my family over the years, and never a problem. I don't understand why people claim to have so many problems, and always say they're junk.
There is a really nice case study on CPI injection with scannerdanner, that to me is a fuel pump on his way out , i want to say when is cold, battery gets a little weaker and fuel pump wont make the psi required , those CPI are very finicky aparently, if you dont have the exact psi required it will never start,i bet that truck will soon will get hard to start even in hot weather,you found a vaccum leak but i think thats a different problem,have them jumpstartit whe they have the problem.
Thatis the Vortec spider system. All the injectors are hidden inside the manifold plenum. I have the earlier version of the same system in my '93 Sonoma. Works well. Earlier CPI systems have an all aluminum manifold with the throttle body mounted on the front of the plenum facing the fan. Newer systems have the throttle body mounted on top of the plenum.
exactly what I needed tonight thanks Eric! You always come through with the goods
you're the best Eric does the GMC Jimmy
Eric, i used to own a 97 of the same vehicle and my intake above the throttle body had the same little screw to hold it down and it had a big clamp around the base to secure seal to the throttle body.
Crusty radiator and oil cap is typical of all of my well maintained 4.3s. These run 200,000 plus easy if maintained. I have owned and driven 6-8 high mileage units over the last 15 yrs or so. Most have lost coolant but I keep everything cked and filled.
Mine has 311k but I'm currently having issues with it.
You can get a cigarette or cigar and pull of a vacuum hose and blow smoke in it and where smoke comes out at is a vacuum leak. It works for me and makes it easier to find leaks.
Where the intake elbow mounts to the throttle body there should be a metal clip that helps hold the intake elbow down onto the throttle body and the wing nut holds it down on the rear.
Thank you for that explanation. I have a 2000 Jimmy and I have similar problems. I imagine to just go OEM parts for this truck?
Delphi or AC Delco MPFI conversion spider is the only way to go. This updated part includes the regulator. Not sure if the plastic fuel lines inside the intake are included, but they should all be replaced at the same time.
LOVE IT
Thanks for showing the scan tool that your using.Most of the time, I purchase the same tools that your using in your vids.
My first car was a Honda Civic and it was constantly having issues. was a 2001 and my sister owns a 2002 and its about to crap out on her too. thats why I got rid of it and got a 2006 chevy cobalt. never had one single issue with it so far. props to american cars.
I love these diagnosis vids. Great stuff, Eric.
That's an interesting point about advanced timing. Doesn't the PCM advance the timing electronically?
Some are a conversion kits and some fitment is necessary. .They do not use the old style Poppet.
map sensors also play a big part in turbo systems to monitor boost ect and in the uk turbos are super common.
I'm having an issue along the lines of this. It's a 2002 Chevy 2500HD with the 6.0 Vorteck with a throttle cable. Not electric throttle. . On days when it's below 25 degrees. When I start it. It starts right up. The rpm kicks up to 1000 like normal but after 5 seconds the rpm drops to the point where it barley is running. It's sputters at a very low rpm for around 30 seconds and then picks back up to 1000 rpm. Then several seconds later it will drop back down and barley run. It will either stall out or continue this until the engine temp picks up a bit. After that it runs perfect. On warmer days it starts right up and runs perfect. It runs very well and doesn't burn oil. I don't think it's fuel related as it has new fuel pump, filter and lines. It did this before and after the new pump. It idles normally when it's not doing this. Plus It's been doing this for as long as I can remember. My father got this truck in 2003 and it's now mine after he bought a new truck. It's done this ever since he's gotten it. I'm stumped and can't find a solution, any suggestions.
I have the same exact problem when it gets cold. I went through the whole ordeal of checking fuel pressure, all good. Turns out it's the cheap ass plastic wheel on the ignition key module that gets stiff when it gets cold. I've learned to simply turn the key switch very slowly until I feel the spring tension and then crank-it starts every time without having to tear out the column and replace it with an even worse chinese aftermarket POS.
I love the GMC Jimmy's and you are the best
wow , thanks so subjective.... oerrrr I mean descriptive
Hmm, never had starting issues with my Explorer, never had rusty coolant. But then again I actually take care of my vehicles and perform regular maintenance.
Dude. Your the man. Its taken a while to find your stuff but thanks heaps
I know this video is old, but I drive an '02 Blazer and there is supposed to be a metal clip that holds that resonator tight to the front end of the throttle. The clip is missing on this one.
Every time I have a problem like this it's either a temp sensor (I.A.T. or coolant) or it's a vehicle that's never seen a tuneup EVER. I've never worked on one of those though, as I've been warned to stay as far away from the spider injection systems as possible.
the oring that sits around the top of that plug is a known issue with those! both my 98 and my 03 GMC had it and as for spider the earlier spider you can rebuild! I have a mfi spider that I had in my 98 but couldn't find pophet for it so I got a junk yard one from a 01 and replaced all the legs and seals and works perfect! my 03 has the mfi as where my 98 has cfi and I couldn't tell a real difference
I have Gmc Sonoma 2000 know it starts some days and not other it ran all summer no problem. My thoughts was wire's has not Ben change since the purchase of vehicle. I'll check for leakage.
one way too check for vacum leak,indentify fuel trims are high at idle.Then raise rpm,s-if fuel trims start going back too normal you have a vacum leak.Also + 5.4 on bank 2 ftft I wouldnt say is excessive.Rule of thumb is if its under 5% its ok...good luck
Thanks for that info.
Are you looking to buy new or used? Basically anything that is slow is a good car as a first car. If you are looking for new and fuel efficient I would say a Fiesta or a Focus but I am a Ford fan, but it could easily be a Chevy Sonic. There really is a lot to choose from depending on budget.
awesome video again, I just recommend the double finger cross when working on chevy's
Couldn't spraying water on the electrical parts like that short them out and damage them?
I have a 2000 Blazer and am hoping to see you replace the spider injector assy. I was told that if you remove the throttle body and look into the upper part of the intake and see fuel (wet) that is an indication of a failing spider. Also random misfires and that is what mine is doing now. I read also that the spider was redesigned and that the new style has 6 individual injectors instead of one multi injector unit. It is a direct replacement.
those are wonderfuel(sarcasm), i've done dozens in my gm days, used aftermarket a few times in a pinch, never any real issues, but mostly used O.E parts since it was a stealership, also fuel prime MUST be at min 59psi or hard cold start occurs(it'll run on 52, so don't let that fool you thinking no fuel delivery problem)
Sometimes I forget they're on.
Had a 1989 with a throttle body injection with an intermittent cold start problem. Turned out to be the fuel pump relay. Just a little tidbit for you.
I have 1999 GMC Jimmy with 4.3. Never had a problem with it starting cold until we just replaced the fuel pump. Does this have a cold start valve? It runs fine on warm days, and I have to jump on cold days cause it drains battery. What do I look for to fix problem?
I've got the same problem on a n14 pulsar after running on some sort roads. I'm hoping it's just vacuum or maybe plugs as it's past service
Hi ETCG. That could be the crankshaft position sensor failing. I have a totally different car, but the basic concept is the same.
Mine was acting up in cold mornings but not in hot weather. The starter would turn the engine without a problem, but the injection computer didn't know the engine was turning, so it didn't inject fuel. Now, sensor replaced, and the engine always starts :) Hope you can find the problem.
My air injection pump had a few cracked vacuum lines. fix them and the fuel trims went back to normal
I had a similar problem. Car died all of a sudden and then would refuse to start. It turned out to be the fuel pump connectors that somehow seemed to work themselves loose. Of course my engine is has near as makes no difference 500k km and has a myriad of electrical gremlins. But that GM LHO 3.1 V6 sure is a tank it just keeps on chugging along and breaking down occasionally usually due to wiring issues or sensor failures.
I don't know, I just always thought than if you take your car to somebody you trust, that you'd have secured the ability to pay for up to what the vehicle's value warrants. This guy lost the diag fee and by the time they are of the means to deal with the problem things will likely have gotten worse.The best thing that could happen now is that it progresses to where it fails smogcheck and either fix it right or junk it.
Air condition problem when turned on air conditioner would engage clutch know does not
I've never been to nor heard of a shop that don't charge for diagnostics. If he let the customer walk without paying it's on him or the shop he works for.
I'm thinking about moving up to a truck from a car. Would like a Diesel, but they're too expensive. Seen one of these on CL. A 2001 w/ 145k miles. Any thoughts on Sonomas? I'd say I'm pretty mechanically inclined, do all my own maintenance. I kind of know what to look for on a used gas engine. Leaks, dirty filters, low fluids etc. I just don't want to waste time checking it out if it isn't worth it. I haven't really seen to many of these on the road.
I have these models over the years. reliable. decent mileage if u drive like a sane person. loads of info on them. tough as nails.
Thank you for the videos Eric. Really appreciated!!
Hi Eric, how would you go about adjusting the Carburetor choke in hot weather? Thanks.
I have a 95 Chevy 3500 with a 454... when I go to start it when the engine is cold, it fires right up but I have to feather the throttle to keep it running, it tries to load up with gas and occasionally will backfire through the exhaust, this happens only for about a minute then it clears up and the truck runs perfect.... it only does this at the initial start when the engine is cold, if it has any engine heat it starts and runs perfect. Any help is appreciated.