polish_ambassador

Hello,

I have a 1991 4.9L 2wd f150.
i bought this rig for 1$ with a fresh tranny and other goodies. anyway, original owner told me the problem was the injectors were clogged from sitting for a couple years cause he was getting fuel pressure and spark. Anyways, i replaced the injectors along with the intake gaskets, egr and tube, etc. so now my issue is the fuel pumps don't want to prime. I have replaced the fuel pump relay along with the tank selector switch hoping that was the issue. It wasn't, the EEC relay and Fuel pump relay do both click every time the ignition is turned on. So after probing around i noticed the tank selector switch is not getting power in any of the red wires (i am however receiving 8v in the blue/yellow and yellow/white wires. Causing the fuel to show way passed full on the dash). The inertia switch was pushed in for whatever reason so i popped the red button out, as i did that i checked to see if that was getting voltage and it wasn't.

If any one has any idea of what it may be or what i should test please help me out

kd3pc

fuel pump not priming...

check fuel pressure in teh engine compartment and then walk back towards the tanks...check filter along frame rail.

methinks you should have 12voltsDC pretty solid 12volts at the pump. Check voltage at the pump relays, the inertia switch voltage needs to be checked, pushing it in may make mechanically, needs to make electrically.

wiring diagram would help

best of luck

polish_ambassador

both pumps are actually getting 12v when i tripped the FP relay. So i figure the pumps are bad. I'm going to replace them this weekend and see if that makes a difference

polish_ambassador

turns out both pumps were bad along with both tanks rusted out.