fuel pump not shutting off

[broughton88]

hey guys i need help... i got a 88 2.9 and the first fuel pump/fillter on my truck the one behind the drivers fender well wen i turn the key the pump will turn on and it doesnt turn off evan wen i turn the truck off i have to keep turning the key off and on a bunch of times and then it will turn off and sometimes wen im driving it will spit and sputter so i shut the truck off and the fuel pump is off so i just turn the key and the pump turns back on and it runs fine wtf! is this fuel pump soposeto stay on wen the trucks running becasue i thought it just turns on for like 8-10 seconds and shuts off?? i had a eletrical fire a wile ago and had to run a wire from that fuel pump to the relay for it to turn on... i didnt have that wire hooked up all summer but now that its winter one day it just wouldnt start so i hooked that wire up to the fuel pump and it started??? i dont no if that will help you guys figure out the problem this is just really f**ked up. sorry if this makes no sense and you think im stupid but this is wats happening i just need some leads to help me figure out this problem..thanks

 

[Psychopete]

Fuel pump will run 2 time for 1-2 second each when the key is first put onto run. Once the engine is running, it runs continiously.

The computer must still be on when you're turning it off because the computer controls when the fuel pump is on by grounding the relay from pin #22 on the PCM. The relay also depends on the ECC relay to be switched on for the positive end of the relay circuit.

I'd be curious where you tapped the fuel pump circuit into. Not sure with out seeing what you have going on, I would highly suggest investing into a vehicle specific wiring diagram.

Pete

 

[DisturbedMXer8]

You could also have a short somewhere that is somehow bypassing the computer controls. Try and get to the main wiring and take a look at it, see if you can't find something that looks odd or out of place.

 

[broughton88]

i got the wiring diagram from my friend thats a mechanic we ran the wire from the fuel pump power wire im guessing to the fuel pump relay because it burned wen i had the fire.. the relay also clicks when the fuel pump stays on after turning the truck off is that a bad relay... iv repaced it so manny times. or could it be somthing with the computer

 

[broughton88]

pete it sounds like you no what your talking about do you know of anythings i could check right away to try to elimanate the problem

 

[Psychopete]

pete it sounds like you no what your talking about do you know of anythings i could check right away to try to elimanate the problem

Check your ECC relay. It's the brown (IIRC) plugged relay on the passenger side. Green plug I think is the fuel pump relay. If you pull the ECC relay while the fuel pump is stuck running, does the fuel pump stop running?

Pete