Fuel pump questions

[Blue88Coupe]

1990 5.0

I used to be able to switch the ignition key on and have the fuel pump primed and active when the car was being cranked, its no longer doing that.

Im not getting any voltage to the pink/black wire that goes down to the fuel pump.

The fuel pump shut off switch(what ever its called, black box red button) is depressed down, you cant press it any futher. Is that the normal state or is it supposed to be up?

I cant remember if I was getting any juice to the relay under the drivers seat or not, i will check again tomorrow.

My questions are if the button is supposed to be up on the shutoff switch then how do i get it back up. and if im not getting any juice to the relay under the seat where do i need to check?

Thanks
-Nick

[JimD]

Inertia should be flush, up means its popped. For the relay power comes from a fuse link(brown18 ga). Power to the relay wire is O/LB.
PM me a email and ill send you the wiring diagrams when i get home for lunch, fixing to go to work here in a sec.

[greenbullitt]

Agreed. If the inertia isnt popped,The pcm isnt firing the relay, you have a bad relay, or a wiring issue.

[Blue88Coupe]

Inertia should be flush, up means its popped. For the relay power comes from a fuse link(brown18 ga). Power to the relay wire is O/LB.
PM me a email and ill send you the wiring diagrams when i get home for lunch, fixing to go to work here in a sec.

Does the brown fuse link come off the solenoid with the other fuse links?

[greenbullitt]

Does the brown fuse link come off the solenoid with the other fuse links?

Going off memory, it should

[Blue88Coupe]

Ive got pink/black darkgreen/green red/black orange/green.

The dark green is always hot even with the key out. None of the other wires get hot during ignition

[greenbullitt]

Ive got pink/black darkgreen/green red/black orange/green.

The dark green is always hot even with the key out. None of the other wires get hot during ignition

they should all be hot as theyre straight off the batt...pm me for my # if you need help

[Blue88Coupe]

they should all be hot as theyre straight off the batt...pm me for my # if you need help

if they're all hot then how does the relay know to switch on?

On another note, i've got the fuel pump hardwired on trying to start it. It will hit a few times then it just dies. I cant keep the thing running.

I've brought the #1 piston up, put the distributor on #1 and the fuel pressure is at 32.

It doesnt have a EGR valve, the wires that went to that sensor are just hanging. The IAC valve is hooked up.

Its getting spark.

The spout is out.

[JimD]

Sorry man, my modem took a shit at lunch, i just sent you the mustang diagrams. What exactly are you looking for on the tahoe. I can get any diagram off alldata, just finished a 2000 chev silverado 5.3 motor job at work today also, I'd save all the sensors esp the knock sensors, they were over $100 for the pair(they are under the intake).

[greenbullitt]

if they're all hot then how does the relay know to switch on?

On another note, i've got the fuel pump hardwired on trying to start it. It will hit a few times then it just dies. I cant keep the thing running.

I've brought the #1 piston up, put the distributor on #1 and the fuel pressure is at 32.

It doesnt have a EGR valve, the wires that went to that sensor are just hanging. The IAC valve is hooked up.

Its getting spark.

The spout is out.

Bump the fp to 40, advance the dist to keep it running...call me

[Blue88Coupe]

Bump the fp to 40, advance the dist to keep it running...call me

FP at 40 got it going for about 3 or 4 seconds then it peters out.

I need to find an EGR block off plate. I had a piece of ductape over the hole and apparently you cant ghetto rig it that way. I imagine its sucking air through that hole and dying.

[Blue88Coupe]

Sorry man, my modem took a shit at lunch, i just sent you the mustang diagrams. What exactly are you looking for on the tahoe. I can get any diagram off alldata, just finished a 2000 chev silverado 5.3 motor job at work today also, I'd save all the sensors esp the knock sensors, they were over $100 for the pair(they are under the intake).

I dont really know what I want. I have the harness, I need to figure out after I get an ecc how to wire it up to run standalone and what sensors are involved.

[Blue88Coupe]

If I jumper the green wire to the pink/black wire at the relay it will turn on the fuel pump and I can start the car, however the pcm is still not firing the relay when I turn on the key. I've jumper'd the clutch switch and the neutral safety switch, the car will fire. When I cut the key on im not getting any voltage to the orange/green wire that goes to the pcm. What could be causing the PCM to not fire the relay?

Also do any of you know what this connector is supposed to goto:

[greenbullitt]

a relay

[Blue88Coupe]

a relay

Its the wide open throttle cut out relay

I've finally solved the fuel pump issue. Some wires were not connected to cause the ECM relay to fire which in turn fires the fuel pump relay. Its all good in the hood now. And unfortunately I know more than I ever wanted to about fox body wiring.