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No power at fuel pump

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My1GLaser

15+ Year Contributor
1,565
31
Dec 4, 2006
Bartow, Florida
I will try to be brief and thorough. I do not have power at the fuel pump. I do have power at the no. 10 terminal on the EFI control relay in the center console. I also have tested the relay itself per the Haynes manual and it checks out fine. The ign. fuse on the battery + terminal is fine also and has power. I also tried running the jumper wire from the test connector on the firewall and I get nothing at the pump. (It was the only single connector on the firewall on the pass side) Any idea what the problem is?
The car has not run for 4 months. I am doing a major overhaul and it did run before the teardown. I have power everywhere else on the car except the B+ wire to the radio. I am thinking that there might be a problem in the ignition circuit somewhere. I had the car tore down to bare body...nothing in engine compartment or passenger compartment. I personally checked and connected every wire and did not find any shorts or damaged wires. So, I am at a loss here. The car will turn over, but of course not run. This was supposed to be a glorious day of the first run of my car, but I guess I will have to wait for some input from the tuners. :thumb:
 
Theres a lot more that runs off the ign circuit than the radio and the fuel pump. You need to focus only on the fuel pump circuit right now. If you really trust yourself that the system is 100% and the test connector did not give you power at the pump, you have a break somewhere between the MPI relay and the pump. Check for power at the fuel pump connecter on the backside of the tank. you should get power at the black wire with the white stripe. no power verifys a break or bad relay. make sure you can actually hear the relay click, or check for power directly out of the relay. realys are cheap, throw one in there if your still unsure. If you have power, check for ground on one of the other wires, i foget which one it is on the fwd but one is a constant ground, most likely the all black wire . if you have both power and ground, take out the sending unit and see which wire is not connected or suspect a faulty fuel pump

also, im wondering why you completely stripped the car, i work on cars all day everyday and its hard enough sometimes to remember how things were when a job lasts more than a day or two, i couldnt imagine stripping an entire car, or a reason behind it. just dosent seem logical to do this to a modern car to me. stripping one area at a time maybe...
 
As for your curiosity, I got the car from someone halfway stripped with the motor out and I just finished the job. I cleaned, painted, replaced anything worn out. I've been wanting a project like this for a while, so I didn't mind the process. I bagged and tagged all the bolts so I wouldn't forget where they went. I actually have a 94 1.8L that I am using for parts and reference. It had a mint interior and was very handy to have as a donor car.
Anyway, when you say sending unit what do you mean? As for the fuel pump it is a new Walbro 255HP that I just installed. I checked power at the plug end going to the tank and get nothing. And yes, I hear the relay click when I turn the ignition. Unless I have other issues related to these 2 power issues, I am very tempted to just do a rewire on the pump and run a new constant to the radio. I figured there was possibly a break from the relay to the pump, but I wasn't sure if it ran thru the fuse box somewhere before going back to the pump. (I don't have the fuse box cover in the passenger compartment to show all the fuse designations.)
 
The fuel pump isn't powered from pin 10on the MPI circuit but from pin 3 which is the power from the ignition circuit. Check it for power and ground pin 7 on the MPI relay to switch power to pin 2 feeding the fuel pump. Make sure that the pump has a good ground and that the feedthrough wasn't broken installing the Walbro.

The fuel pump check connector should be a black wire with a white stripe. Same at the pump end but at the relay I believe it's a black w/green stripe.

Keep in mind that normally the power to the pump isn't turned on until you run the starter.

Steve
 
Thanks to DSMracer & Steve for the wire colors. Apparently when routing the harnesses these firewall test connectors did not make it back into the stock positions and I was connecting to the Tach connector for timing, idle etc. not the fuel pump one. Anyway, my fuel system is primed and the car fired right up. Not bad for a total rebuild for the first time. :rocks:
 
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