Fuel Issue

[Chatmanboy]

I was in the process of doing the IAC reset procedure and as im adjusting the iac screw the car cuts off, not from adjusting the screw. Now when i turn the key on the fuel pump doesnt prime. I checked the fuse its good and replaced the fuel pump relay, still nothing. Then i jump the singal wire under the coil pack (not the green one) and still nothing just the clicking of the hotwire relay. So i cant wrap my head around thins one and need you guys help

 

[Chatmanboy]

Could it be the fuel pump? Can they just go out like that or do they start showing signs of getting weak?

 

[BRAD_PADGETT]

Could it be the fuel pump? Can they just go out like that or do they start showing signs of getting weak?

My stock one failed just like that eight years ago. My Walbro 340 failed just like that two weeks ago after seven years. Yes it can be the fuel pump. Brad

 

[Chatmanboy]

ok. so i swapped the fuel pump and still nothing. Should i hear the relay on the passenger side click when i jump the fuel pump or turn the igniton on?

 

[BRAD_PADGETT]

ok. so i swapped the fuel pump and still nothing. Should i hear the relay on the passenger side click when i jump the fuel pump or turn the igniton on?

Check the hot wire kit 20 amp fuse. My kit has the fuse by the alternator. When my last pump died it also took out this fuse. Brad

 

[Chatmanboy]

That fuse is still good... i went thru this test, and it failed on the part i put red!

Basic FP circuit T/S Tree
Unplug the fuel pump relay.

Check for 12 VDC at pin D on the FP relay harness using a body/chassis ground. Is power present?
If yes: Continue to section A.
If No: Proceed to section B.


Section A

Hook a DMM up between a chassis/body ground and pin A of the FP relay wiring harness. Turn the key on while watching the DMM. You should see 12 VDC for 2 seconds. Do you see this?

If yes: Proceed to section A1

If no: Turn off ignition and leave the fuel pump relay unplugged Gain access to the ECU (passenger side kick panel). Back probe wire A1 (either dk green/white or grn/blk depending on the schematic you look at) and turn on ignition. Is 12 VDC present for 2 seconds.

If yes: A problem exists in the wiring between the ECU and the fuel pump relay.

If no: Unplug ECU connector A (don't forget to unplug the ecu memory wire at the battery and turn of the ignition) and check for continuity between A1 and ground. If continuity exists there is a problem (short to ground) in the wiring between the ECU and the FP relay. If no continuity exists the ECU is at fault.

Section A1

Check for continuity between FP relay harness pin C and body/chassis ground.

If continuity is present (should be less than one ohm) see section A2

If continuity is not present a fault exists in the wiring between FP relay pin C and body/chassis ground.

Section A2

Locate the Grey "prime connector" on the passenger side of the engine compartment. Check for continuity between the "prime connector" and FP relay harness pin B. If continuity is not present a fault exists in the wiring between the FP relay and the pump.

If continuity is present connect the FP relay harness to the FP relay. Connect a DMM between "prime connector" and body chassis ground and turn the key on. 12VDC should be present for 2 seconds.

If 12 VDC is present and your pump doesn't run a the problem is either your pump or a broken wire or faulty connection in the wiring going to your pump or a faulty ground at the tank.

If 12 VDC is not present your problem is either a faulty FP relay or the wiring between the FP relay and the pump. (broken before the prime connector or shorted)
I left out the trouble shooting for this because I'm unsure of the resistance between the prime connector and ground. There should be continuity because the FP in a load in that circuit I'm just not sure how much.

Section B

Check FP/INJ fuse.

If fuse is good check that FP/INJ location in fuse block has 12 VDC present with the key in the RUN position. If 12VDC is present a problem exists in the wiring between FP/INJ fuse and the FP relay harness.

If power is not present you'll need to figure out why the ignition switch isn't applying power there.

 

[Chatmanboy]

This harness looks real bad to, this may be the problem

 

[Chatmanboy]

anyone know how the wiring is ran to the fuel pump?

 

[Chatmanboy]

ok i cant not figure this out the fuel pump work outside the tank. so i know its someting with wiring. is there a way to run a another fuel pump circuit?

 

[Jerryl]

anyone know how the wiring is ran to the fuel pump?

Look at post #18 in the sticky.

 

[Chatmanboy]

ok last post about this...

So i check everything,
fp/inj fuse good
Stock and Hotwire relay clicks when ign is on, so doesnt that mean good?
New oil sensor
Yet pump still doesnt prime? I put a new one in nothing, so i took the out and ran it with the battery and it wound right up

Now when you guys say grounded where should i be looking? Just the grounds under the compressor and the oil sensor wires?
I also read that if tps is out of wack and will put the ecm into clear mode and cut off fuel? is that true if so would the fuel pump not prime because i do have my tps loose...

 

[Jerryl]

. . . .
Now when you guys say grounded where should i be looking? Just the grounds under the compressor and the oil sensor wires?
I also read that if tps is out of wack and will put the ecm into clear mode and cut off fuel? is that true if so would the fuel pump not prime because i do have my tps loose...

Tap into the ground wire at the tank and check for continuity.
If the tank is in place, tap into the wire and jump it to a known good ground.
Clear flood mode does not effect pressure, just injector pulse.

 

[Chatmanboy]

Isnt the stock ground wire for the tank inside the trunk? also when i turn the ign on i noticed the fuel gauge is past the F and i dont even have a full tank

 

[Chatmanboy]

Well the problem was my fuel sender unit.







Now I just need to find out what caused this. But the car is up and running