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 shits 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. Any responses without the words "cliffs notes please" will be met with Rep!!

Please HELP!!

 

I spent another hour or so digging through the chassis harness for anything obvious and I still could not find anything. Just for clarity's sake, after checking again last night:

-black w/ white stripes = 12v when the ignition is "on"
-black w/ yellow stripes = one of them is power for the fuel pump, the other, I cannot find the end.
-black w/ pink stripe & bands = I have no idea.

Anyone at all have any input at all?! This is driving me nuts!!

The FSM is not helping me here.

 

i feel your pain bro. actually, the same thing happened to my sr. unfortunately, i still havent gotten it running. i thought it was the ignitor chip on mine. it wasnt. then i replaced the CAS. that didnt work either. i still have no spark. i hope you get this problem fixed. sorry i couldnt help.

 

hmm.....u might need to ground your EGI thats what martin did to my old hatch, or hit up durdan

 

I assume the EGI is grounded in the stock electrical configuration. Why would removing the fuel pump relay unground the EGI if that is the case? Nothing really changed here. I drove the car home the day before I removed the fuel pump relay. The only thing that was changed was that the fuel pump relay was removed from the car. Why would this make the ignition not fire? I'm so goddamn frustrated at this point its ridiculous. It's got to be something really simple, yet I can't figure out what it is. Go figure a technical thread is posted in the Nissan tech forum and it gets practically no responses.

There has got to be someone out there that has more knowledge than me when it comes to the electrical systems in these fucking pieces that can chime in here.

grrrr

 

if thats the case you need to hit up nico or freshalloy

 

LOL, ya, I posted this there before I posted it here.

 

bump

 

check the cam position sensor.
That extra plug on the dizzy.
If that sensor isn't functioning properly then the ecu won't allow spark or fuel. I've found that if the plug has ben plugged and un plugged a few times, it will get worn out and not make a good connection.
I wouldn't assume that your fuel pump is the problem. I doubt your ignition is the problem considering you are not getting both spark and fuel. Thats an ecu problem. That sensor seems to cause it quite a bit.
Sometimes it is so bad that it won't do anything, other times, it will cause the EGI and EGI pump relays to tweak out... have someone try to start the car and put your hand on those relays, they should click once. if they click a bunch of times, then that sensor is tweaking.
Good luck.

 

Just for discussions sake:

I am having fuel and spark related electrical problems. I need insight! - FreshAlloy.com Forums

I am having fuel and spark related electrical problems. I need insight!: 240SX Technical Forum: Nissan Forums / Infiniti Forums - NICOclub