Fuel pump issue! / Fuel pump relay? (Electrical Challenge!)

[maj Andres]

Whats up Niconauts!

First of all this is a 95 with s14 SR20det. I took it to a GHETTO a** body shop to pull out this dent that was on the passanger side and to replace the fudged up door that was on there with another one that is in way better condition. They did a pretty good job in pulling out the dent and installing the door. But get this...you ready? I went to start my car and it would just turn and turn but would not start! So after a while i figured that I wasn't hearing my loud a** fuel pump (Walbro 255lph). So I hit the FSM hard. This is what i've got.

ALL fuses checked out good. So...

Here's a head scratcher for you guys

(This is EC 201 from S14 USDM FSM)

So I turn my IGN to ON and I'm getting my 12V at the FP relay terminals 1,2 and 3 EXCEPT @ terminal 5... the relay is not clicking close thus not delivering the 12V to turn on my fuel pump.

I put this relay in a place where another relay exactly like this one was and I could feel it clicking.

I checked the continuity of the FP relay harness from pin #5 all the way to terminal 1 on the fuel pump connector and it showed good continuity.

Pin 2 on the fuel pump connector is showing good continuity to ground.

I tried checking continuity from Pin 2 on the FP relay to the ECU but I couldn't get anything...I checked allll the connections on the ECU harness..BUT wait....

I ran a jumper wire on the FP relay harness from #1 to #5, turned IGN to ON and my fuel pump turned on and kept on going and going. YAY, my fuel pump isn't broke

Took key off, inserted and turned to ON then took the key out very quickly and the fuel pump primed like it always has...this confirms that the ECU is indeed sending that short signal to the pump?? But how?! the relay was not inserted and thus it had no way of it getting any type of signal.

Anyone have any clue as to why the relay is not closing in that particular socket? I just don't get it

Does anyone see any real danger to bypassing the relay? I don't see any besides the pump running for too long after you turn to ON but don't start the car.

[maj Andres]

Wait! just cause i'm getting 12V at #2 on the relay doesn't mean that the coil is energized!

Just means that the 12V is making it's way through the coil. It needs the GROUND from the ECU! which it's not getting. GRR... what did those f*** do to my car! Well looks like i'm going to have to tear some s*** out to figuere out WTF happened.

[boatflipper]

Andres, I know this is a reallllllly old post but this is what's happening with my wife's QX4. Did you ever figure out what was happening? I talked to an Infinity mechanic and he believes it's the computer itself.
Here is my thread: post6448756.html#p6448756
Thanks a bunch.

[maj Andres]

hello boatflipper,

when they pulled the dent from my car, it was coincidently right next to my ECU...so when they pulled it out, I guess they mashed up all of the grounding wires that make contact with the frame. The ground wires where actually shorting out and thus causing my issue.

To you I say, check those grounding wires. Has anybody messed around in the ECU area? your mechanic just might be right in saying it's the ECU.

Pull out the FSM and check the whole fuel pump circuit. Make sure that everything their is voltage where there is suppose to be, and that grounds are good. Good luck.