Lack of information/ context about the specific situation likely won't yield much help.
Fuel Wiring Diagram
I am trying to troubleshoot my fuel system wiring system. Does anyone have a less complicated diagram of the system so I can trace it from the ignition through the system and back to the TB. The book has that stuff everywhere there has to be a better and much easier way to check all the components within that system alone. Thank you.
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It had a 4.3 now it has a 5.7.What year, engine?
That smart *** comment didn't help provide any info and probably turned away half the guys who could have helped.
Well if you aren't going to give us any info, like what year the truck is, so we can look at the wiring diagram for that year. Or what year the engine is whether it's stock or not. At least post the vin number so we can figure out when it was built and with what electrical system.
Then you need to fill in the info on the swap. What engine, what fuel system. Including carb or injection, brand of those parts, and what fuel pump and or regulator you have.
This ain't supposed to be like pulling teeth. If you want help, explain everything involved in the problem.
Or take it to Tik Tok.
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Well if you aren't going to give us any info, like what year the truck is, so we can look at the wiring diagram for that year. Or what year the engine is whether it's stock or not. At least post the vin number so we can figure out when it was built and with what electrical system.
Then you need to fill in the info on the swap. What engine, what fuel system. Including carb or injection, brand of those parts, and what fuel pump and or regulator you have.
This ain't supposed to be like pulling teeth. If you want help, explain everything involved in the problem.
Or take it to Tik Tok.
You must work for Microsoft tech support.It had a 4.3 now it has a 5.7.
What specific engine do you have in it now? Which 5.7?
And what wiring is there going to the fuel pump. If it still has the "stock" wiring, then what year truck is this and I guess it had the 4.3, but which 4.3 if there were multiple options for your year (TBI, CPI, SMPI).
There are literally dozens of wiring diagrams for the fuel pumps on S10s over the years and variants. Nobody is going to have the information you need if they don't know what you have.
Not following. I asked for the fuel system wiring diagram for 96 chevy blazer. Did not know that because I swapped out the 4.3 vortec for the 5.7 vortec that the wiring from the ignition to the tank to the relays and finally to the MFI would change. I also indicated that I would like it to include the information from the ignition to the now 1997 5.7 votec engines' spider vortec MFI system. Has custom harness made for the 5.7 to plug and play with the blazer harness. Made by Current Performance. They also re did the ECM from the 97 5.7 to match up with the 96 blazer. Power is at the MFI. As noted earlier I will start with the in tank pump that required some type of wiring change when I installed it and work forward from there. To your point if I knew all of the little details to help you figure it out then I wouldn't need to be on this forum to begin with and that is being a smart ***.That smart azz comment didn't help provide any info and probably turned away half the guys who could have helped.
Well if you aren't going to give us any info, like what year the truck is, so we can look at the wiring diagram for that year. Or what year the engine is whether it's stock or not. At least post the vin number so we can figure out when it was built and with what electrical system.
Then you need to fill in the info on the swap. What engine, what fuel system. Including carb or injection, brand of those parts, and what fuel pump and or regulator you have.
This ain't supposed to be like pulling teeth. If you want help, explain everything involved in the problem.
Or take it to Tik Tok.
Am I missing something here??
Let me quote your original post. There is no mention of 1996 or a Blazer.I asked for the fuel system wiring diagram for 96 chevy blazer.
If CPW provided the wiring harness then they are who you should be talking to. Although I have heard they aren't much help post delivery.Discussion Starter · #1 · May 25, 2023
I am trying to troubleshoot my fuel system wiring system. Does anyone have a less complicated diagram of the system so I can trace it from the ignition through the system and back to the TB. The book has that stuff everywhere there has to be a better and much easier way to check all the components within that system alone. Thank you.
The wiring from a 4.3 Vortec in a 96 Blazer to a 5.7 Vortec should require no alterations to the wiring to the pump. If you modified it, that's the problem.
I suspect your issues is with the fact that 5 of the 6 4.3 pins get moved to a new location on the computer and of course then the additional 2 computer grounds are added for #7 & 8. Plus providing the 2 additional pink ignition power wires in the pod for 7 & 8.
I do not have a 96 5.7 computer pin out or I'd post it for you. Just need to find one for a 96 Silverado IF you are still using the 96 PCM. If CPW provided a newer style one, post the service number. Likely an 0411.
I am using the PCM from the truck I got the motor from, and it was flashed to marry up with the rest of the 96-blazer wiring such as the lights, axle distance, or fuel system. Your correct about the modification to the wiring on the in-tank pump. When I received the pump, it came with instructions on how the wiring had to be for the new style plug being used on the pump vice the harness. I ordered a 96 blazer in-tank pump and that is how it came so I made the alterations based on that. I am planning to drop the tank back down and do the testing on the harness this week. I believe others have had the same wiring instructions for that item.Let me quote your original post. There is no mention of 1996 or a Blazer.
If CPW provided the wiring harness then they are who you should be talking to. Although I have heard they aren't much help post delivery.
The wiring from a 4.3 Vortec in a 96 Blazer to a 5.7 Vortec should require no alterations to the wiring to the pump. If you modified it, that's the problem.
I suspect your issues is with the fact that 5 of the 6 4.3 pins get moved to a new location on the computer and of course then the additional 2 computer grounds are added for #7 & 8. Plus providing the 2 additional pink ignition power wires in the pod for 7 & 8.
I do not have a 96 5.7 computer pin out or I'd post it for you. Just need to find one for a 96 Silverado IF you are still using the 96 PCM. If CPW provided a newer style one, post the service number. Likely an 0411.
Which you haven't identified. Can you post a pic of the label on the PCM? That would help a lot.I am using the PCM from the truck I got the motor from
I see you finally identified the vehicle as a 1996 Blazer. The stock wiring for the 1996 Blazer, the fuel pump relay is in the glove box. It gets battery power to the switch points on one pin (either 87 or 30, I don't remember which), and switched ignition power for the coil on another pin (85 or 86, again, I don't remember which) The other switch point pin (30 or 87) goes to the fuel pump and the other coil pin (86 or 85) is grounded by the PCM.
Check the fuse in the fuse block, drivers side end of dash. Try swapping the horn relay (if the horn works) with the fuel pump relay in the "relay center" in the glove box. If that doesn't work, you can try jumpering the 30 and 87 slots in the relay socket and see if that makes the pump run. If that works, and you have ignition switched voltage (check with a volt meter) on one of the coil slots in the socket, then your issue is the ground from the PCM.
Do not drive it jumpered, and do not drive it with it rigged with an extra ground wire to the coil so the pump always runs with the key on. I had a friend spend nearly a year in the hospital with severe burns all over his body because someone did that to a used car he bought, and in a moderate colision, he had a broken leg and a concussion, and a broken fuel line that sprayed fuel on the exhaust. The pump never shut off. You don't want to put yourself or your family through that.
Thank youWhich you haven't identified. Can you post a pic of the label on the PCM? That would help a lot.
I see you finally identified the vehicle as a 1996 Blazer. The stock wiring for the 1996 Blazer, the fuel pump relay is in the glove box. It gets battery power to the switch points on one pin (either 87 or 30, I don't remember which), and switched ignition power for the coil on another pin (85 or 86, again, I don't remember which) The other switch point pin (30 or 87) goes to the fuel pump and the other coil pin (86 or 85) is grounded by the PCM.
Check the fuse in the fuse block, drivers side end of dash. Try swapping the horn relay (if the horn works) with the fuel pump relay in the "relay center" in the glove box. If that doesn't work, you can try jumpering the 30 and 87 slots in the relay socket and see if that makes the pump run. If that works, and you have ignition switched voltage (check with a volt meter) on one of the coil slots in the socket, then your issue is the ground from the PCM.
Do not drive it jumpered, and do not drive it with it rigged with an extra ground wire to the coil so the pump always runs with the key on. I had a friend spend nearly a year in the hospital with severe burns all over his body because someone did that to a used car he bought, and in a moderate colision, he had a broken leg and a concussion, and a broken fuel line that sprayed fuel on the exhaust. The pump never shut off. You don't want to put yourself or your family through that.
That is a 1996-2000 Vortec PCM. The hardware shown was used on the 4.3L V6 as well as Vortec 5000 and Vortec 5700 V8s. It was even used on Vortec 7400 engines in Express/Savanna vans. That's the top number, the "Serv. No 16229684."
I'm getting conflicting search results online for the firmware number. Some places are crossing that to a 4.3L V6, others are crossing it to a C2500 which would definitely be a V8. Others have it for C1500/K1500 with either the V6 or either of the Vortec small block V8s.
I would guess it's currently set up for the Vortec small block V8 you have it running now, so you'll need the pinouts for that engine to find the fuel pump relay ground wire connection on the PCM connector if you need to check continuity and check whether the driver for that is working (providing a ground pulse to prime when first powered up with ignition power, and providing a solid ground when the engine is turning as indicated by the crankshaft position sensor).
I'm getting conflicting search results online for the firmware number. Some places are crossing that to a 4.3L V6, others are crossing it to a C2500 which would definitely be a V8. Others have it for C1500/K1500 with either the V6 or either of the Vortec small block V8s.
I would guess it's currently set up for the Vortec small block V8 you have it running now, so you'll need the pinouts for that engine to find the fuel pump relay ground wire connection on the PCM connector if you need to check continuity and check whether the driver for that is working (providing a ground pulse to prime when first powered up with ignition power, and providing a solid ground when the engine is turning as indicated by the crankshaft position sensor).
Now that is solid information. The vehicle it came out of, according to the farmer I got it from, was a 97 2500 Silverado. The engine (5.7L Vortec) and ECM with harness came as a package deal. So, where do I find this pinout chart or diagram for said engine?That is a 1996-2000 Vortec PCM. The hardware shown was used on the 4.3L V6 as well as Vortec 5000 and Vortec 5700 V8s. It was even used on Vortec 7400 engines in Express/Savanna vans. That's the top number, the "Serv. No 16229684."
I'm getting conflicting search results online for the firmware number. Some places are crossing that to a 4.3L V6, others are crossing it to a C2500 which would definitely be a V8. Others have it for C1500/K1500 with either the V6 or either of the Vortec small block V8s.
I would guess it's currently set up for the Vortec small block V8 you have it running now, so you'll need the pinouts for that engine to find the fuel pump relay ground wire connection on the PCM connector if you need to check continuity and check whether the driver for that is working (providing a ground pulse to prime when first powered up with ignition power, and providing a solid ground when the engine is turning as indicated by the crankshaft position sensor).
You might check this thread...if what you need isn't there, you can get info from Alldata.Now that is solid information. The vehicle it came out of, according to the farmer I got it from, was a 97 2500 Silverado. The engine (5.7L Vortec) and ECM with harness came as a package deal. So, where do I find this pinout chart or diagram for said engine?
*Attention Searchers* Black Box to 0411 PCM Wiring Info...
Here are the PCM pinouts from AllData for both the 1999 4.3l (was in my Blazer) and a 2002 Chevy Express 5.7 Vortec. I used this when I did my swap in winter 2011/2012 and it went great. This is for changing from the black box computer to a 411. The new V8 injector pod plug is also attached a...
www.s10forum.com
1996-1997was not the 0411 PCM.
Try logging in at AutoZone.com. They have wiring diagrams for some vehicles of this era. You have to "create an account" and log in. It's free.
If none of those options work, AllDataDIY is available. It costs a monthly subscription. I can't remember if it's single VIN or just a few. You'd need the donor VIN, or a similar VIN with the same engine and drive train.
Your local public library might have an auto repair database that has wiring diagrams.The engine (5.7L Vortec) and ECM with harness came as a package deal. So, where do I find this pinout chart or diagram for said engine?
Try logging in at AutoZone.com. They have wiring diagrams for some vehicles of this era. You have to "create an account" and log in. It's free.
If none of those options work, AllDataDIY is available. It costs a monthly subscription. I can't remember if it's single VIN or just a few. You'd need the donor VIN, or a similar VIN with the same engine and drive train.
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