HELP!!! Fuel problem

[daddy_ja]

I dont get it. I replaced my fuel pump, fuel relay, fuse is good, inertia swith isnt popped, but still no damn fuel pressure. What the heck am i missing here???

Here is more info on my situation. I was out riding around on some bumpy roads, as i was crusing along i felt the fuel cut out for a second and come right back on, a little later it did it again, then a few miles later the truck completely shut off. well i couldnt hear the pump kicking on so i towed it home thinking the pump went. Today i replaced the pump, relay, and checked the interia and fuse, but i still cant here the pump kicking on and there is no fuel pressure. What do i do now?

Oh, and a few weeks ago i noticed a puddle of fuel under my truck after i started it, could an injector be leaking? and would that cause me to have no pressure and the truck not start?

If i want to check and see if im getting power to the pump, what kind of voltage would i be looking for? I was planning on pulling the connector by the tank and testing to see if there is power getting back there. But im kind of dumb when it comes to electrical stuff.

 

[DeRocha]

As you may already know the fuel pump will only run when given 12v... When you turn the key from run to start the inertia switch (pictured below) will see 12v (both wires) for only 2 secs or while the tac registers > 0 RPM. After 2 secs of zero RPM the computer will shut off the fuel pump relay and you'll only see ~7v at the inertia switch and fuel pump. Seeing 7v is weird but that is what you'll get if you check the wiring. Anyway check out/search threads such as

Fuel pump not working for more info...

 

[daddy_ja]

Update,

I found out the EEC fuse was blown, so i replaced that and it started back up. Well a few minutes later it popped again, now everytime i turn the ignitian on the fuse pops, what now? A short somewhere? where should i look?

 

[shamaal]

You want figure 7. http://www.autozone.com/servlet/UiB..._us/0900823d/80/0b/a9/c7/0900823d800ba9c7.jsp
Pull everything in the circuit (Fuse 8?) and replace until it pops. If you've got a meter you can disconnect the battery and measure resistance to ground at the fuse and look for the short. You do have the correct fuel pump relay I assume.

 

[daddy_ja]

You want figure 7. http://www.autozone.com/servlet/UiB..._us/0900823d/80/0b/a9/c7/0900823d800ba9c7.jsp
Pull everything in the circuit (Fuse 8?) and replace until it pops. If you've got a meter you can disconnect the battery and measure resistance to ground at the fuse and look for the short. You do have the correct fuel pump relay I assume.

I have the relay they gave me at Checkers, i would assume its right. i will put the old one back in seeing how i now know that was not the original problem.

 

[daddy_ja]

You want figure 7. http://www.autozone.com/servlet/UiB..._us/0900823d/80/0b/a9/c7/0900823d800ba9c7.jsp
Pull everything in the circuit (Fuse 8?) and replace until it pops. If you've got a meter you can disconnect the battery and measure resistance to ground at the fuse and look for the short. You do have the correct fuel pump relay I assume.

according to the diagram it goes to the A/C, but how do i pull the A/C out?

 

[shamaal]

To answer the question, the A/C line goes to the Wide Open Throttle (WOT) relay. It's one of the three in the same box as the Fuel Pump Relay.

What I would do, assuming no meter to read resistance to ground. Buy a ****pot full of 15A fuses (still assuming #8 is problem child). Resist urge to use larger fuse and look for smoke! Get a Haynes, manual follow along on the diagrams and ask questions.

Assumptions:
a) #8 PDP fuse blows
b) Fuse blows whenever inserted or key is turned to on (not start)
c) If fuse blows ONLY when car is started - open inertia fuel shutoff switch and try again. If fuse does not blow problem is shorting wire near the fuel pump connector. This is a common problem, the insulation breaks down and cracks exposing wiring.

If fuse blows when car is in run not started yet, (b in assumptions) I would pursue the following line of troubleshooting.

1. Remove EEC power relay and unplug PCA.
2. Does fuse blow; yes bad wiring; no insert EEC relay
3. Does fuse blow; bad relay (note without PCA plugged in EEC relay is not energized)
4. Unplug ICM, Mass Airflow sensor, cannister purge solenoid, remove WOT and fuel pump relay.
5. Plug in PCA If fuse blows bad PCA (pins 37/57) OR a shorted fuel injector, there's a big ass plug for all the injectors to isolate them but I don't remember where it is, perhaps the one on the alternator bracket.
6. Fuse good: insert/plug in items one at a time from step 4 until it blows, troubleshoot circuit.
7. Fuse still good? Car should start, you have an intermittent short to ground or a bizarre problem.

Pay attention to the assumptions, particularly c, and respond if there are questions. I'm changing my driver's seat today but I log on occasionally.

Good Luck!

 

[daddy_ja]

i do have a meter, im just confused on how to use it. lol

 

[daddy_ja]

ok, here is what i did. I used a 12V brake light bulb and soldered wires to each lead, then i stuck the wires in the fuse slots. Next i turned the key on and started wiggling wires until the bright glow started to dim. Didnt take long to find it after that. It turns out its a wire bundle in the engine bay that is shorting, havent found the exact spot yet, but i know which wire. So after a new fuel pump, fuel relay, and 5 30A fuses, all i needed was a $2 bulb and some electrical wire! Go figure

Lesson learned......always trouble shoot before you start replacing parts!!!! Dont assume you know whats wrong!!!

And i must say...Thanks a ton for your help!!!! i really appreciate it!