fuel pump wiring problems??

[93 x]

so here is the deal every time i hit a bump the car wants to stall out and then jumps in rpms or dies. i at first thought it was a problem with the maf sensor because every time i jiggled the intake tube it would jump up in rpms. so today when the car was off i jiggled the tube and then i heared the fuel pump turn on, then off then on again every time i moved the tube and that makes sense because the iac valve opens up every time it jumps. so i was just hoping anybody had a simalar problem or any input would be great because i have been dealing with this for a couple months now.

thanks a bunch!!

 

[MrShorty]

Interesting. KOEO, the fuel pump should stay off. The PCM only triggers the fuel pump "pressure up" sequence (pump comes on for a couple of seconds then goes off) only when the PCM first gets power. If I've correctly interpreted your description of the fuel pump behavior when you jiggle the intake, I would suspect that there is a loose connection in the PCM power circuit, probably at the relay/near the air filter, that is making/breaking connection when you jiggle the intake. The relay is inside the power distribution box which is right next to the air filter housing. A loose connection in PCM power could also cause the intermittent stall/stumble behavior.

 

[93 x]

I was just reading a few of your articles and you deffiniley know what you are talking about, but i tried to wiggle every wire there was around. but i did start by wiggling the relay, but nothing happened. So where is the pcm on these explorers so i can check that out. this is just such a pain in the ass because i got it to do the problem a million times in a row but now it wont do it im getting angry!!

 

[93 x]

sorry I just double read your statement. So the relay wiring for the pcm is your main suspect? Maybe if I remove the whole power box off the firewall I can duplicate the problem. I also did forget to mention that i was teaching my kid cousin about cars so i would remove a relay or disconect something and would have him figure it out and put the thing back but that was my first main suspect when i was looking things over but i never got deep into the power distrbution box. thank you very much for clearing up how the fuel pump really works