I used to think Q-jets were junk until I met a guy named John Angeles. They were good enough for his Firebirds so they must've been good carbs...and they definitely are. They are getting hard to find but any time and effort spent on a good Q-jet will pay big dividends. Thanks for posting an informative video. Next to pasta the Q-jet will always be my favorite carb!!
Could you show how to replace the garter spring and cup on a late sixties Quadrajet 4 barrel? I just rebuilt the original carb on my 1969 Grand Prix and I had to order this separately, cause the one in the kit was junk! Thanks! Can I do this without removing the Carb again?
I have had fairly good success rebuilding these carbs both for factory stock engines & slightly modified street engines. I run one on my 88 Dodge 1 ton van.The warped top plate & body is a common problem that I like to call "The MaGilla Gorilla" concept of carb fixin. That is, tighten the hell out of the mounting bolts & that will fix all. If the top plate (cover) is severely warped I have straightened them on an arbor press. I use feeler gauge stock on the ends & carefully apply pressure to the center. Use some sort of soft material like aluminum or wood to protect the casting. Keep adding feeler stock or shim stock on the ends until most of the warpage is gone. I use a large belt sander to finish bringing the plate completely flat. Warped body. Easily detected by looking at the slot that the little secondary divider plate slides into. If the slots are fairly parallel then it is good to go. If the slot is wider at the top than the bottom then the body is warped to the point that it will cause a problem. I have taken a 1" thick plate of steel & drilled 2 holes to accept the primary venturii accelerators so that the body will sit flat on the plate of metal. Then I drilled & tapped 2 holes to accept a 5/16" bolt through the front carb mount holes. This will hold down the front end of the body. Then I drilled & tapped a couple of holes to accept 1/2" X 13 bolts. These are for a pair of machinist's mill toe clamps so that I can apply pressure to the rear of the body. Start by putting about .010" feeler stock across under the body just forward of the secondary throttle opening bores. tighten the 2 5/16 bolts. You'll notice that this will raise the rear of the body slightly off the plate of steel. Take the machinist's clamps (called toe clamps) & tighten them until the carb body is flat against the steel plate. Let it sit for a while to stabilize , remove & check for flatness. If not flat add some feeler stock & repeat the process. I start w/ about .010" & increase in increments of .005" until the body is flat. Feeler stock: feeler gauge that comes in 10 or 12" lengths. Don't know where you could find them locally. Toe clamps: You might contact someone who runs a machine shop, they could help find some & show you how to use. I could include pics but don't know how to do that through U-tube. I know this is complicated but it is the best explanation I can offer. The carb body is made of a zinc alloy & is quit malleable, will not crack when you straighten it. I have tried straightening the body on an arbor press but didn't have much luck. Again I don't know what supplies you have where you are but here are some things I use for cleaning. To clean the large parts I use a 50/50 mix of simple green & water. Let it sit overnight & it will remove most of the grease & varnish. If the carb has bass floats I use something called CLR cleaner (calcium lime rust remover). A local brand here is ZEP CLR. There is also a name brand CLR. To clean the corrosion that accumulates in the float bowls CLR also works real well. Don't leave it in there for too long, it will damage the casting. Rinse with hot water to neutralize the chemical action of the cleaner. Good luck, I can answer questions as best as possible.
Excellent Video! Took my early Q-Jet apart 3 times now looking for the answer to my problem. Then this video explained it. I have the same crack mentioned, but can only see it with a 10x loop. Mine has a strange problem where if you put your hand in front (nowhere near the primary butterfly's) of the carb and restrict the fan flow, the RPMs drop. Also as soon as I place the air cleaner on top (without screwing it down) the RPMs drop. I thought maybe the mixture screws were too loose and letting air in but that isn't it. Did yours exhibit something like this before you got the airhorn flat? Thanks
It has been a while, but I'm sure that almost all air leaks will contribute to a fast and rough idle. Can you run your car and press your hand on the air horn where it is cracked. If it runs different, you need to repair or replace your airhorn. If you are in America like most of my viewers, I would try to buy one with a better airhorn, there should be enough around. You could spend all day trying to get your bad one to seal, and fail.
Make sure you get that air cleaner stud through to the bottom of the carburetor. What I didn't quite explain is that with a thread on the base plate and a nut on top of the air horn, that stud will press down on the air horn instead of pulling it up. The pressing instead of the pulling may just eliminate the air leak, cracked or not. Best of luck to you.
Yes those are good suggestions. I have a 1/4-20 stud in there. I think it engages the center body, not the airhorn (over an inch thread engagement), and when I tighten down the wingnut I don't hear any changes. The car is a 64 lemans and it runs pretty well except for a 1 sec hesitation in the secondary. I will keep my eye out for a better airhorn that isn't cracked.
I did your suggestion of tightening a nut down over the stud to pull the airhorn down and that just about eliminated my issue. Now I can barely here a drop in RPM when I put my hand in front of the carb or when I put the air cleaner on. Thanks again for your video's and suggestions.
@@StopTheRust that little tit bit of information about the nut on the stud was explained to me today by Jim at Perth Carby centre almost word for word!
They are an excellent carb, people who don’t know what they are doing with them, ruin them and therefore repairs are needed. People who don’t know what they are doing with them, don’t know how to adjust them, so they tell everyone they are rubbish.
I'd check and see if the secondary air dam's are opening, if you open it up and choke the primaries you should see it open. You should then see the needles lift in the center and that should let fuel in. If all that's happening and there's still no fuel in the secondary's then you're going to have to pull it apart. If you're not confident then look into getting that book I mentioned it the video. Good luck
I have an old carter unit that is bolted up to my 350. It runs but it's crazy rich and the linkage on the secondaries is messed up. It also seems to have the infamous leaky fuel bowl issue. And it bogs, sometimes backfires. Someone also put an electric choke on it and messed around with the linkages on that side. Got any tips on overhauling it? It appears to be an 800cfm model shockingly enough.
I actually got it apart and I'm totally shocked at how clean it is. Quadrajets tend to get filthy in America cause of the cheep gas. It needs some adjustments, But no warping at all. The needle valve is strange however, never seen one like it.
Hi thnxforthe vid,,,Im bogging going up a hill and going on the hwy ,,soon as \i put a load on it ,it boggs and pumps until i release the gas a bit ,,it clears after a minute but freaks me out all the time ,,, yes i checked vaccuum hoses ,, help
The bigger issue is shaft ware vacum leak and fuel well leakage leading to flooding both are fixable little tricks like shaving the pump shaft for more squirt and drilling the primary's for big came
I suppose you could be loosing vacuum to a leaking gasket, or the "wrong" gasket may be blocking vacuum signal from somewhere. Sorry I couldn't help more.
I just uploaded a video rein-acting the technique, make sure you start with the best one you can find. check the updated description for the video link
The only thing about this video is that you don't show how to fix warping. Just mentioning that you used a piece of wood to not damage the carb, isn't good enough for most people. Also, there are other methods like simply sanding or grinding a warped airhorn as long as its very minimal.
I used to think Q-jets were junk until I met a guy named John Angeles. They were good enough for his Firebirds so they must've been good carbs...and they definitely are. They are getting hard to find but any time and effort spent on a good Q-jet will pay big dividends. Thanks for posting an informative video. Next to pasta the Q-jet will always be my favorite carb!!
Finally!!! You are awesome! I had a weird noise like that from a train, now i know why! Thx man
Nice basic rundown. Any and all Quadrajet fix videos are welcome. I am starting to tinker with them myself.
+MrZayne thanks I made these because I couldn't find anything I needed on youtube. Not many people tinkering with these.
Could you show how to replace the garter spring and cup on a late sixties Quadrajet 4 barrel? I just rebuilt the original carb on my 1969 Grand Prix and I had to order this separately, cause the one in the kit was junk! Thanks! Can I do this without removing the Carb again?
Donald Smith I'm sorry I haven't worked on these for a long time. I definitely recommend the book.
Thanks and work I have plenty of. It has been two years since I touched the Quadrajet on my daily driver and she purrs nicely.
I have had fairly good success rebuilding these carbs both for factory stock engines & slightly modified street engines. I run one on my 88 Dodge 1 ton van.The warped top plate & body is a common problem that I like to call "The MaGilla Gorilla" concept of carb fixin. That is, tighten the hell out of the mounting bolts & that will fix all. If the top plate (cover) is severely warped I have straightened them on an arbor press. I use feeler gauge stock on the ends & carefully apply pressure to the center. Use some sort of soft material like aluminum or wood to protect the casting. Keep adding feeler stock or shim stock on the ends until most of the warpage is gone. I use a large belt sander to finish bringing the plate completely flat. Warped body. Easily detected by looking at the slot that the little secondary divider plate slides into. If the slots are fairly parallel then it is good to go. If the slot is wider at the top than the bottom then the body is warped to the point that it will cause a problem. I have taken a 1" thick plate of steel & drilled 2 holes to accept the primary venturii accelerators so that the body will sit flat on the plate of metal. Then I drilled & tapped 2 holes to accept a 5/16" bolt through the front carb mount holes. This will hold down the front end of the body. Then I drilled & tapped a couple of holes to accept 1/2" X 13 bolts. These are for a pair of machinist's mill toe clamps so that I can apply pressure to the rear of the body. Start by putting about .010" feeler stock across under the body just forward of the secondary throttle opening bores. tighten the 2 5/16 bolts. You'll notice that this will raise the rear of the body slightly off the plate of steel. Take the machinist's clamps (called toe clamps) & tighten them until the carb body is flat against the steel plate. Let it sit for a while to stabilize , remove & check for flatness. If not flat add some feeler stock & repeat the process. I start w/ about .010" & increase in increments of .005" until the body is flat. Feeler stock: feeler gauge that comes in 10 or 12" lengths. Don't know where you could find them locally. Toe clamps: You might contact someone who runs a machine shop, they could help find some & show you how to use. I could include pics but don't know how to do that through U-tube. I know this is complicated but it is the best explanation I can offer. The carb body is made of a zinc alloy & is quit malleable, will not crack when you straighten it. I have tried straightening the body on an arbor press but didn't have much luck. Again I don't know what supplies you have where you are but here are some things I use for cleaning. To clean the large parts I use a 50/50 mix of simple green & water. Let it sit overnight & it will remove most of the grease & varnish. If the carb has bass floats I use something called CLR cleaner (calcium lime rust remover). A local brand here is ZEP CLR. There is also a name brand CLR. To clean the corrosion that accumulates in the float bowls CLR also works real well. Don't leave it in there for too long, it will damage the casting. Rinse with hot water to neutralize the chemical action of the cleaner. Good luck, I can answer questions as best as possible.
THANK YOU FOR POSTING THIS VIDEO!!!!!!!!!!!!!!!!!!!!!
Finally something really useful about Quadrajets,thanks man,i love those carbs !
Can you make a video showing the heating and hammering process you used? Hard to find info on issues like these. I much appreciate it!
Excellent Video! Took my early Q-Jet apart 3 times now looking for the answer to my problem. Then this video explained it. I have the same crack mentioned, but can only see it with a 10x loop. Mine has a strange problem where if you put your hand in front (nowhere near the primary butterfly's) of the carb and restrict the fan flow, the RPMs drop. Also as soon as I place the air cleaner on top (without screwing it down) the RPMs drop. I thought maybe the mixture screws were too loose and letting air in but that isn't it. Did yours exhibit something like this before you got the airhorn flat? Thanks
It has been a while, but I'm sure that almost all air leaks will contribute to a fast and rough idle. Can you run your car and press your hand on the air horn where it is cracked. If it runs different, you need to repair or replace your airhorn. If you are in America like most of my viewers, I would try to buy one with a better airhorn, there should be enough around. You could spend all day trying to get your bad one to seal, and fail.
Make sure you get that air cleaner stud through to the bottom of the carburetor. What I didn't quite explain is that with a thread on the base plate and a nut on top of the air horn, that stud will press down on the air horn instead of pulling it up. The pressing instead of the pulling may just eliminate the air leak, cracked or not. Best of luck to you.
Yes those are good suggestions. I have a 1/4-20 stud in there. I think it engages the center body, not the airhorn (over an inch thread engagement), and when I tighten down the wingnut I don't hear any changes. The car is a 64 lemans and it runs pretty well except for a 1 sec hesitation in the secondary. I will keep my eye out for a better airhorn that isn't cracked.
I did your suggestion of tightening a nut down over the stud to pull the airhorn down and that just about eliminated my issue. Now I can barely here a drop in RPM when I put my hand in front of the carb or when I put the air cleaner on. Thanks again for your video's and suggestions.
@@StopTheRust that little tit bit of information about the nut on the stud was explained to me today by Jim at Perth Carby centre almost word for word!
They are an excellent carb, people who don’t know what they are doing with them, ruin them and therefore repairs are needed. People who don’t know what they are doing with them, don’t know how to adjust them, so they tell everyone they are rubbish.
Agreed. So it would be more accurate to say they are NOW rubbish.
Yeah there’s not many good ones left anymore. I’ve got a good one and it’s awesome. Highly adjustable and variable.
Had the same problem about 15 years ago exactly what I did before RUclips
Not my doing second hand one I picked up fixed it
I'd check and see if the secondary air dam's are opening, if you open it up and choke the primaries you should see it open. You should then see the needles lift in the center and that should let fuel in. If all that's happening and there's still no fuel in the secondary's then you're going to have to pull it apart. If you're not confident then look into getting that book I mentioned it the video. Good luck
I have an old carter unit that is bolted up to my 350. It runs but it's crazy rich and the linkage on the secondaries is messed up. It also seems to have the infamous leaky fuel bowl issue. And it bogs, sometimes backfires. Someone also put an electric choke on it and messed around with the linkages on that side. Got any tips on overhauling it? It appears to be an 800cfm model shockingly enough.
minniemation Buy the book mentioned in one of my quad videos, you need it.
Will do, I ordered a rebuild kit a couple hours ago. It's a rare carb so my only hope is it isn't warped.
Don't worry you can fix a warped air horn. The one on my daily driver was warped and rebuilt about three years ago, I haven't touched it since.
I actually got it apart and I'm totally shocked at how clean it is. Quadrajets tend to get filthy in America cause of the cheep gas. It needs some adjustments, But no warping at all. The needle valve is strange however, never seen one like it.
I have been told that float level adjustment on these is very sensitive, and slight error will make a dog of a motor.
Hi thnxforthe vid,,,Im bogging going up a hill and going on the hwy ,,soon as \i put a load on it ,it boggs and pumps until i release the gas a bit ,,it clears after a minute but freaks me out all the time ,,, yes i checked vaccuum hoses ,, help
How's the accelerator pump ? I think you call it something else in the USA, the squirt piston when you open it up, check it out.
Thanks! means, a lot! now i have gas in secondaries and it runs way more better!
The bigger issue is shaft ware vacum leak and fuel well leakage leading to flooding both are fixable little tricks like shaving the pump shaft for more squirt and drilling the primary's for big came
Will the wrong base plate gasket keep you from pulling vacuum to set the air metter screws.
I suppose you could be loosing vacuum to a leaking gasket, or the "wrong" gasket may be blocking vacuum signal from somewhere. Sorry I couldn't help more.
We all have problems, if one of yours is a Quadrajet this might be a good place to post it, I'll try to help.
There is a company out there re popping new ones. I found it on eBay motors it’s completely brand new they even give you jets.
thermal expansion bad if not taken into consideration!
what to search for if the secondaries have no gas?
Need a ball and spring video
Tienes un video en español
A great carb !!!
over tightening them ruin's them.
BE VERY CAREFUL.
I just uploaded a video rein-acting the technique, make sure you start with the best one you can find. check the updated description for the video link
0:26
i have a problem
The only thing about this video is that you don't show how to fix warping. Just mentioning that you used a piece of wood to not damage the carb, isn't good enough for most people. Also, there are other methods like simply sanding or grinding a warped airhorn as long as its very minimal.