Intermittant fuel pump issue, Help please

[Killet]

88 B2 with manual transmission, 4wd, the intank fuel pump was replaced a couple months ago as it just stopped working. It stopped working again just before I got home the other night. Once I was home I turned the key on and heard no fuel pump come on, tried it probably 20 times over a couple hours, nothing. In the morning, vehicle had not moved, tried it and the pump came on and the B2 ran fine. I figured the pump was going so I replaced it with a new one, got finished and the pump came on with the turn of the key, B2 started, I drove it for about 5 minutes...figured all was well. Next morning, turn the key on and the pump doesnt come on and run, B2 wont start.... Ive straight wired thru my inertia switch so I dont think thats the problem ...is there a relay or solenoid I should check before trying to trace the wires looking for a short? It wont run right now and Im leary of driving it anywhere if it does at this point.

Any guidence would be greatly appreciated!

 

[AllanD]

The fuel pump not running is more likely a symptom rather than a cause.

You MUST understand how things work before you start messing them up.

Bypassing your inertia switch? Why? they practically never go bad.

The fuel pump is turned on by the fuel pump relay which is turned
on by the PCM.

 

[mhughes165]

.....u wasted alot of money on fuel pumps, its your relay, they all like to shit out and work intermittiently

its on the indder fender area, directly back from the starter solenoid, you will have a PCM relay and a fuel pump relay, replace both, and u shouldnt have problems for a LONG time

 

[Killet]

my inertia switch was bad, I should probably replace it but right now its jumpered out. Im getting power at the inertia switch plug when I turn the key on but neither fuel pump comes on now. I put a meter on the elec connector at the fuel pump on the rail and got nothing when the key is turned on. I may be able to unplug the fuel tank connector without dropping the tank again and check it there but after I replaced the fuel pump it came on and ran. Wiring under the B2 looks fine, no visible damage. When I turn the key I hear what Im guessing is the relay clicking every time.

As before any suggestions would be appreciated, Thx guys

 

[holyford86]

check your ground wires for continuity to chassis ground, check your power wires for continuity back to the relay. either of these not having continuity will cause the fuel pumps to be inoperative.

 

[Killet]

Thx guys, looks like it was one of the relays as MHughes suggested. Fortunately I have a pair of 88 b2's....(well sometimes I dont think its fortunate ) After reading the responses here, I swapped the green one out and it came right on, swapped it back and nothing came on...off to get a new one I suppose, Thx again!

 

[AllanD]

Yeah, typically on an '86-88 the relays are either left unmounted
(dangling on their wires) by some previous "mechanic" attempting
to diagnose a problem or break off of their sheet metal brackets

If the relays hang from their wires they tend to get water inside them
which doesn't do them any good.

On an '89-92 the relays are mounted underneat the underhood fuse box

'93-up they plug into sockets in the fusebox where they are far more accessable

for completely understandable reasons fuel pump relays don't fail all that often on the later trucks.

AD

 

[Lost]

i have this exact problem!

94 ranger 2x4, 2.3L, manual, reg cab.

i have the same issue with the pump sometimes coming on and sometimes not. I had replaced the pump asuming this was the problem, but no change. I also checked the inertia switch, relay(bought a new one at Autozone and even swapped the EEC relay as it is the same part #) and fuse, still have the problem.

In AllanD's post, he mentioned the PCM(powertrain control module?), could this be the issue? (the picture in the Haynes manual is different than what i see on my firewall, if in fact it's the same part)

Please help! I do realize this is an old post, but hopefully someone is still here who knows my issue.

Thanks!