My man I know you're being paid by the job but good Lord slow it down a touch, you're not in the stealership Lol. Is it caffeine? Anyway if you could make a quick video showcasing your diag connectors/equipment and share some links to them I would be eternally grateful. I know AESwave makes good stuff. Your videos and thought processes are excellent, that one with the school-bus A/C was a nightmare situation.
@@advancedleveldiagnostics Lol I believe it. I just noticed this morning you had an Amazon store link to the tools you use/recommend, my bad. Making test lights is relatively easy but I'm going to buy one of those Jarhead ones to support an American-veteran. They seem very well-made. You have a new subscriber, appreciate you taking the time to share everything with us.
This was a good reminder of a topic I haven't thought about in years. So, I did a quick google search to better understand why that resistor is there. The resistor is brought in line with the fuel pump feeder wire to reduce voltage applied to the fuel pump during times when demand is expected to be low, at idle. This prolongs the life of the fuel pump and reduces cabin noise. It is controlled by that special relay. During starting the resistor is bypassed by the relay, so the car started fine. It wouldn't idle because as soon as that relay flipped over to bring the resistor in line, the pump got no voltage because the relay connector was open. With so many cooling fins and bulk, you know that resistor is wasting energy, so the overall design seems clunky. I'll guess that more modern designs would use a PWM circuit, abandoning the resistor much like old blower motor resistor designs are outdated. Bravo to you, for showing the design with a memorable case study.
I work on these vans all the time and it's a very common mistake that someone would easily forget to plug that fuel pump resistor module back in which is mounted as part of the cowl. The 2-piece plastic and metal cowl typically needs to be removed to do a few services such as spark plugs and strut replacement, windshield replacement, etc. I once forgot to plug that connector back in and the van started and stalled, but eventually found out what I forgot after a couple minutes of thinking after a spark plug replacement job. It will happen from time to time even to the best of us. More often than not it's something simple that's often overlooked. Great job and thanks for the video.
Very good to know! Thanks. In Toyota fuel pump systems, the resistor, often referred to as the fuel pump resistor, plays a crucial role in controlling the voltage supplied to the fuel pump. Here’s a detailed explanation of its functions: Regulating Fuel Pump Speed: The resistor helps in regulating the speed of the fuel pump. By reducing the voltage, it can lower the pump speed during certain conditions, such as low engine loads or idle. This helps in maintaining the appropriate fuel pressure and flow rate, improving fuel efficiency and reducing noise. Fuel System Pressure Control: By controlling the fuel pump speed, the resistor helps maintain consistent fuel system pressure. This is important for the proper functioning of fuel injectors and ensuring the engine gets the correct fuel-air mixture for optimal performance. Preventing Overheating: During low-demand situations, running the fuel pump at full speed continuously could lead to overheating. The resistor helps in reducing the voltage and hence the operational speed of the pump, preventing excessive heat buildup. Extending Fuel Pump Life: By not always running at full power, the fuel pump experiences less wear and tear, which can extend its operational life. The resistor contributes to this by adjusting the pump's working conditions. In summary, the resistor in Toyota fuel pump systems helps manage the fuel pump's speed, maintain proper fuel pressure, prevent overheating, and extend the life of the fuel pump by adjusting the voltage supplied to it based on the vehicle’s operational requirements.
I had a Tacoma with this problem. It spent 6 weeks at another shop who thought it was a security issue due to start/stall. Resistor was open circuit (corroded). We charged 1 hour for diagnostics. Got a customer for life. Great channel!😊
Gm had that same fuel pump resistor set up in the early nineties. It was intended to make the fuel pump output more consistent by maintaining a constant 12 volts to the pump. When cranking, it gets full 12 volts from the battery. After start up the charging system voltage goes higher so they put a resistor in series to limit voltage to the pump. Kind of a low tech precursor to the duty cycled pump.
That's cool. It has 2 fuel pump relay, one is fuel pump relay and the other one is circuit opening relay. The fuel pump relay send power to the fuel pump when cranking and under full throttle. The circuit opening relay send power to to the fuel pump relay but then the ecm ground the fuel pump relay so power goes through the resistor then to the pump to limit the current to the fuel pump the control the speed of the fuel pump. Good diag, it's hard to figure it out if there is no code , but the good thing you had the fuel pressure gauge. Thanks for the video.
KP Falconi Maybe like a fuel pump control module. Great comment btw. I learn a lot from the comments. This channel is the real deal. His truck is sooo cool. His wife must b on board because she lets him buy all the tools he wants.
Toyota are the worst for loosing there idle memory if the battery has been disconnected, the initial symptom gave that impression so I was not surprised you cleaned that throttle body first. Cheers.
Im not familiar with this specific circuit but it likely rund the fuel pump through the resistor once running and bypasses it during cranking. Either to reduce the pump noise or reduce the current flow. Jeep used to do this too. Funny thing was they resurrected an old ballast resistor from the 70's. Great video, my guess was fuel pump the way it died slowly.
This same thing happened to one of my techs when replacing valve cover gaskets. He was sure everything was put back together. After an hour of checking things out, it was that resistor plug that was left unplugged. We both learned something that day. 😂
As soon as you said they removed the intake and after it starts and stalls. I knew it was the resistor that had to be left unplugged. How I knew is I worked for Toyota and had that happen to me
Thanks for sharing nice find guess the schematic would have been helpful. Better yet maybe we should eliminate some of the damm electronics to save a minimum amount of fuel . Thanks for sharing 👍
One thing to remember about fuel pumps or pumps in general. Good fuel pressure does not equal good fuel volume and vice versa. You need good volume in order to make good pressure. If one was able to squeeze the fuel line, pressure will go up but when there is a demand for more fuel (volume) the pressure will quickly fall off.
The resister limits the voltage to the fuel pump while the engine is running, however when its cranking it sends full voltage, that's why it would start and then die.
same concept as early ignition systems ( no bigee ) voltage to coil is straight battery voltage while cranking - then when KOER hot power goes through a resistor.
That's why I like my xtool D8.. It's always charged.. I have a 10ft DLC extension cord if I want to use it anywhere around the vehicle.. I never actually need to, so it's a non issue
You did not waste time. You followed the proper steps. It is impossible to know ahead of time how the vehicle was sabotaged. This reminds me of (remember I am old) vehicles with mechanical contact breaker ignition systems with an ignition resistor bypass to ensure good voltage to the ignition coil while cranking.
@@advancedleveldiagnostics Interesting, USA old tractors? In Western Europe, where I am from, all farm equipment was diesel to prevent harvest fires. A backfire from a gasoline engine can set fire to a harvest.
It seems like cranking bypasses the resistor, which is why it worked on start-up. Then, as you mentioned, it switched to the resistor to lower the voltage.
@@advancedleveldiagnostics Yeah.. I watched a few videos about it after. It's like a mechanical way of getting lower duty cycle control out of it without paying for PWM. Kinda funny.. It works
It's not. The tech working on it was new and did not have much experience and unplugged it by mistake. That's why the shop missed it when they looked over the work.
Can you not either fix the door position switch or disconnect the light until you are able? Seems like you put in an intricate system for a simple problem
During cranking, the relay gives power straight to the fuel pump. After it starts, it sends the power through the resistor to the pump. Since it was unplugged, the pump was not getting power when it was running.
I have a 2007 Camry with the same 3.5 L engine and it's a pain in the ass to change the plugs in the back. When I changed them at 110K, I also replaced all 3 coils with new ones. The coils on the front bank I left alone.
![Voltage Drop Testing With A Test Light? [Part 2]](http://i.ytimg.com/vi/tRUDnaJMnPQ/mqdefault.jpg)
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My man I know you're being paid by the job but good Lord slow it down a touch, you're not in the stealership Lol. Is it caffeine? Anyway if you could make a quick video showcasing your diag connectors/equipment and share some links to them I would be eternally grateful. I know AESwave makes good stuff. Your videos and thought processes are excellent, that one with the school-bus A/C was a nightmare situation.
@@COBRO98 I do have a Snap on coffee machine in my truck😜
@@advancedleveldiagnostics Lol I believe it. I just noticed this morning you had an Amazon store link to the tools you use/recommend, my bad.
Making test lights is relatively easy but I'm going to buy one of those Jarhead ones to support an American-veteran. They seem very well-made.
You have a new subscriber, appreciate you taking the time to share everything with us.
Congratulations on 10k subs!
This was a good reminder of a topic I haven't thought about in years. So, I did a quick google search to better understand why that resistor is there. The resistor is brought in line with the fuel pump feeder wire to reduce voltage applied to the fuel pump during times when demand is expected to be low, at idle. This prolongs the life of the fuel pump and reduces cabin noise. It is controlled by that special relay. During starting the resistor is bypassed by the relay, so the car started fine. It wouldn't idle because as soon as that relay flipped over to bring the resistor in line, the pump got no voltage because the relay connector was open. With so many cooling fins and bulk, you know that resistor is wasting energy, so the overall design seems clunky. I'll guess that more modern designs would use a PWM circuit, abandoning the resistor much like old blower motor resistor designs are outdated. Bravo to you, for showing the design with a memorable case study.
Bravo to you for explanation
@@ivandrago2557 I was expecting you to say "If you understand, you understand". 😅😂
👍
@@abdul-kabiralegbe5660IYKYK.
Great explanation as always! Thanks for sharing!
I work on these vans all the time and it's a very common mistake that someone would easily forget to plug that fuel pump resistor module back in which is mounted as part of the cowl. The 2-piece plastic and metal cowl typically needs to be removed to do a few services such as spark plugs and strut replacement, windshield replacement, etc. I once forgot to plug that connector back in and the van started and stalled, but eventually found out what I forgot after a couple minutes of thinking after a spark plug replacement job. It will happen from time to time even to the best of us. More often than not it's something simple that's often overlooked. Great job and thanks for the video.
Very good to know! Thanks.
In Toyota fuel pump systems, the resistor, often referred to as the fuel pump resistor, plays a crucial role in controlling the voltage supplied to the fuel pump. Here’s a detailed explanation of its functions:
Regulating Fuel Pump Speed:
The resistor helps in regulating the speed of the fuel pump. By reducing the voltage, it can lower the pump speed during certain conditions, such as low engine loads or idle. This helps in maintaining the appropriate fuel pressure and flow rate, improving fuel efficiency and reducing noise.
Fuel System Pressure Control:
By controlling the fuel pump speed, the resistor helps maintain consistent fuel system pressure. This is important for the proper functioning of fuel injectors and ensuring the engine gets the correct fuel-air mixture for optimal performance.
Preventing Overheating:
During low-demand situations, running the fuel pump at full speed continuously could lead to overheating. The resistor helps in reducing the voltage and hence the operational speed of the pump, preventing excessive heat buildup.
Extending Fuel Pump Life:
By not always running at full power, the fuel pump experiences less wear and tear, which can extend its operational life. The resistor contributes to this by adjusting the pump's working conditions.
In summary, the resistor in Toyota fuel pump systems helps manage the fuel pump's speed, maintain proper fuel pressure, prevent overheating, and extend the life of the fuel pump by adjusting the voltage supplied to it based on the vehicle’s operational requirements.
Great explanation, Thanks for sharing!
I had a Tacoma with this problem. It spent 6 weeks at another shop who thought it was a security issue due to start/stall. Resistor was open circuit (corroded). We charged 1 hour for diagnostics. Got a customer for life.
Great channel!😊
Gm had that same fuel pump resistor set up in the early nineties. It was intended to make the fuel pump output more consistent by maintaining a constant 12 volts to the pump. When cranking, it gets full 12 volts from the battery. After start up the charging system voltage goes higher so they put a resistor in series to limit voltage to the pump. Kind of a low tech precursor to the duty cycled pump.
That's cool. It has 2 fuel pump relay, one is fuel pump relay and the other one is circuit opening relay. The fuel pump relay send power to the fuel pump when cranking and under full throttle. The circuit opening relay send power to to the fuel pump relay but then the ecm ground the fuel pump relay so power goes through the resistor then to the pump to limit the current to the fuel pump the control the speed of the fuel pump. Good diag, it's hard to figure it out if there is no code , but the good thing you had the fuel pressure gauge. Thanks for the video.
Nice explanation! Thanks for sharing!
This is the third video from you I watched... You got yourself a new subscriber.
I really like your format.
Thanks!
KP Falconi Maybe like a fuel pump control module. Great comment btw. I learn a lot from the comments. This channel is the real deal. His truck is sooo cool. His wife must b on board because she lets him buy all the tools he wants.
Thank you!
Thanks for help put motor in and hadn't put wiper Cal in yet
Wow! Nice work!! I've been watching your uploads for over a year and you've come a long way! Thanks for the great and interesting content!
Thanks!
Fuel resistor was unplugged but you learned something new that day that what I love about been a mechanic that you learn every day
💯 Well said!
Toyota are the worst for loosing there idle memory if the battery has been disconnected, the initial symptom gave that impression so I was not surprised you cleaned that throttle body first. Cheers.
Im not familiar with this specific circuit but it likely rund the fuel pump through the resistor once running and bypasses it during cranking. Either to reduce the pump noise or reduce the current flow. Jeep used to do this too. Funny thing was they resurrected an old ballast resistor from the 70's. Great video, my guess was fuel pump the way it died slowly.
What was really throwing me off was the way it would jump back to 60psi once the van stalled. Thanks for watching!
This same thing happened to one of my techs when replacing valve cover gaskets. He was sure everything was put back together. After an hour of checking things out, it was that resistor plug that was left unplugged. We both learned something that day. 😂
That's the best training!
As soon as you said they removed the intake and after it starts and stalls. I knew it was the resistor that had to be left unplugged. How I knew is I worked for Toyota and had that happen to me
Experience is the best teacher!
Thanks for sharing nice find guess the schematic would have been helpful. Better yet maybe we should eliminate some of the damm electronics to save a minimum amount of fuel . Thanks for sharing 👍
Congrats on 10K in subs,you deserve it,awesome channel!!! Take care my friend!!
Thank you very much! You're not too far behind, Looking forward!
Sucks to waste a bunch of time only to realize someone overlooked one connector.
BTW, we need another tool bag tour since you upgraded!
One thing to remember about fuel pumps or pumps in general. Good fuel pressure does not equal good fuel volume and vice versa. You need good volume in order to make good pressure. If one was able to squeeze the fuel line, pressure will go up but when there is a demand for more fuel (volume) the pressure will quickly fall off.
Good point! That's why I held the release valve while someone cranked it to check the volume.
Nice catch. I would not have even thought of that.
Thanks for watching!
Very helpful, thank you!!
Thanks for watching!
Love the schrodingers box shout out haha
super fast always enjoy watching 👍
Nice work
Thanks!
Good video.
Thanks!
Wow if you haven't hadn't remembered that it would have cost a lot of money I wish you could find what the resistor goes to thanks for sharing
The resister limits the voltage to the fuel pump while the engine is running, however when its cranking it sends full voltage, that's why it would start and then die.
same concept as early ignition systems ( no bigee ) voltage to coil is straight battery voltage while cranking - then when KOER hot power goes through a resistor.
💯
@@advancedleveldiagnostics 67 YO mechanic - really enjoys your video's
Good video!! Thanks again
Thanks for watching!
That's why I like my xtool D8.. It's always charged..
I have a 10ft DLC extension cord if I want to use it anywhere around the vehicle.. I never actually need to, so it's a non issue
Nice diag bro
Thanks for the visit!
I learnt something new
Thanks for watching! It was new for me as well!
Don’t worry sir. This is how we learn. I bet next time you see something like this you’re gonna have it fixed in 5 min.
💯 I look at the extra time as training.
Wow. Good find. Do you know who unplugged it?
The technician thinks he unplugged it by accident.
where did you get that intake smoke tester adapter ,. the bellow thing you pumped up .. what is it called and where do i get one
amzn.to/4cWiwCD
So there is no pid for that resistor being disconnected? What if it was shorted, any symptoms?
I've never seen a pid for it. If it was shorted I don't think you would be able to tell, it would just run the pump on a higher voltage constantly.
You did not waste time. You followed the proper steps. It is impossible to know ahead of time how the vehicle was sabotaged.
This reminds me of (remember I am old) vehicles with mechanical contact breaker ignition systems with an ignition resistor bypass to ensure good voltage to the ignition coil while cranking.
Thanks! I only worked on those systems on old tractors, but I see what you mean.
@@advancedleveldiagnostics Interesting, USA old tractors? In Western Europe, where I am from, all farm equipment was diesel to prevent harvest fires. A backfire from a gasoline engine can set fire to a harvest.
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By the looks of the diagram.. It looks like the resistor is just a voltage divider circuit so that the pump doesn't get a full 12v. But I'm not sure
It seems like cranking bypasses the resistor, which is why it worked on start-up. Then, as you mentioned, it switched to the resistor to lower the voltage.
@@advancedleveldiagnostics Yeah.. I watched a few videos about it after. It's like a mechanical way of getting lower duty cycle control out of it without paying for PWM. Kinda funny.. It works
Not sure why it was necessary to unplug it to do rear bank coil
It's not. The tech working on it was new and did not have much experience and unplugged it by mistake. That's why the shop missed it when they looked over the work.
Can you not either fix the door position switch or disconnect the light until you are able? Seems like you put in an intricate system for a simple problem
lol, that system wasn't for this; that just broke last night, so the battery was dead. I was just demonstrating how it works.
@@advancedleveldiagnostics ah, ok
Can someone explain why the resistor being unplugged was the issue?
During cranking, the relay gives power straight to the fuel pump. After it starts, it sends the power through the resistor to the pump. Since it was unplugged, the pump was not getting power when it was running.
@@advancedleveldiagnostics Thanks so much. Love your content
I was thinking a MAF unplugged or something simple. first guess
Is not this fuel resistor common to all cars ?
nope
Most other vehicles do not have one.
That was asinine to remove the intake to change just one plug! With 130K and most likely original plugs, all of them should have been done.
I think all plugs were changed and 1 coil.
I have a 2007 Camry with the same 3.5 L engine and it's a pain in the ass to change the plugs in the back. When I changed them at 110K, I also replaced all 3 coils with new ones. The coils on the front bank I left alone.
your video quality is very bad
There's always one. You either need glasses or a better viewing device because it's all crystal clear to me on my computer screen.
@@bernardocisneros4402what do yo mean theres one if you dont like what i said about your videos you can kiss my ass
@@bernardocisneros4402 its not your fucking biasness what i say fuckers