I am having fuel and spark related electrical problems. I need insight!

Post by **detriment** » Tue Nov 06, 2007 4:02 am

I know this is long, but I don't often ask for help here unless I exhaust all options and get completely stumped. I beseech you to read this and give me any input you can!

OK, so here's the deal. Friday evening, I went to a buddies house. When I went to leave i tried to start my car, and it ran for about a tenth of a second and died. Long story short after a couple hours of troubleshooting, we found the problem to be the fuel pump not receiving voltage. All of the relays checked OK, all of the fuses were OK, so I assumed there was a short between the fuel pump relay (drivers kick panel) and the fuel pump. In order to get the car home we hard wired the fuel pump straight from the battery and I drove it home. Saturday afternoon/evening, we gutted my car down to bare metal trying to find this allusive short to no avail. After much frustration I gave up and decided to just re-wire the fuel pump in the trunk with the stock relay (had no money to buy a new one, but it should work). This solved my fuel problem; the fuel line pisses like a race horse. Fuel pressure problem, check. So i re-attach the fuel line and go to start the car, hoping to go get some effing food. Nothing. After about 5 minutes, I pull the coil pack on the number one cylinder (what else would it be?) and alas, no spark. So yea, when it rains it pours.

My question to you all is this: By removing the stock fuel pump relay and re-locating it to the trunk, did I somehow inadvertently disable some check that the ECU needs to see in order to tell the coil to fire?

I thought this may be the case and re-attached the cut wires where the relay was as if the relay was still there and I still do not have spark. I once again checked the fueses/relays for the ignition and, well, i checked every fuse for ****s and giggles. The relays trip, and show no resistance. All fuses are OK.

Heres the scenario:

The fuel pump relay has 5 wires going to 4 prongs. the colors are:

- black with yellow stripe x2- black with white stripe x2- black with pink band.

By testing with my multi-meter (This may be incorrect, Its been a few days and this is off the top of my head since I'm at work) I have discovered the black w/ white stripes to have 12v when the ignition is turned to on. I am assuming the black w/ pink bands is the signal for the relay, and the black w/ yellow stripes is what is a bit confusing. Going to the fuel pump there is one black with yellow stripe as the power for the fuel pump, but the second black with yellow stripe is no-where to be found in the trunk. The 2 black w/ yellow stripe wires come out of the same lead on the relay.

I hate bumming rides to work, and any insight you guys can give me will be much appreciated. I have got to get this solved, and my knowledge of S chassis electrical systems is somewhat limited.

Please HELP!!

Post by **detriment** » Tue Nov 06, 2007 4:03 am

Oh, by the way, I have an s14 zenki with a blacktop s13 SR20DET.

Post by **funigui** » Tue Nov 06, 2007 2:37 pm

http://www.srswap.com/faq/index.asp#harness

read up there, personally i dont know...

Post by **detriment** » Tue Nov 06, 2007 6:59 pm

Im not doing a swap, I put the motor in myself over a year ago. This is something that just recently surfaced as of this weekend.

My main question is this:

What the hell is the second black w/ yellow stripe wire coming out of the fuel pump relay for? Where does it lead and what does it do?

I wouldnt mind knowing what the black w/ pink stripe and bands is for either.

the FSM hasnt been of much help on this one.