Fuel Pump relay fuse question

[mgmgmg]

Ok heres the problem.... Ive posted about this problem before and heard about it in posts. Ok here goes the fuel pump sometimes will not run or whine when you turn the key half way then of course the suv will not start. Ive replaced the fuse relay with a Ford oem fuse and the problem still happens. It doesnt happen all the time maybe twice a month? and it seems only when warm. Ive read that under the fuse box there could be some wire issues. This explorer only has 112,000 miles. Like I said before ive read about this problem but cant seem to find a fix for it. Much help would be appreciated in finding a fix.

Thank you
Ken

 

[FIND]

Ok heres the problem.... Ive posted about this problem before and heard about it in posts. Ok here goes the fuel pump sometimes will not run or whine when you turn the key half way then of course the suv will not start. Ive replaced the fuse relay with a Ford oem fuse and the problem still happens. It doesnt happen all the time maybe twice a month? and it seems only when warm. Ive read that under the fuse box there could be some wire issues. This explorer only has 112,000 miles. Like I said before ive read about this problem but cant seem to find a fix for it. Much help would be appreciated in finding a fix.

Thank you
Ken

Your problem may also be related to the ignition switch. Next time the fuel pump doesnt run when you turn the key, get out and check for power at the relay.

 

[mgmgmg]

I heres what i did... I had my dad with me and when he turned the key half-way i could feel a click and movement on the relay fuse. what i mean i had my hand on the fuse and heard and felt a clicking noise by the fuse. If that answers any questions? Also i have 2 fuses and if i switch them the suv will start???? Im confussed its must be electric? If i tap on the fuse it will start ? Can i get some help.....

 

[FIND]

I heres what i did... I had my dad with me and when he turned the key half-way i could feel a click and movement on the relay fuse. what i mean i had my hand on the fuse and heard and felt a clicking noise by the fuse. If that answers any questions? Also i have 2 fuses and if i switch them the suv will start???? Im confussed its must be electric? If i tap on the fuse it will start ? Can i get some help.....

are you talking about a relay?

or a fuse

 

[mgmgmg]

The black square relay fuse under the hood. Also i did a key off code scan I got 336 thats key off. If that helps i plan on doing a key on next. I did a key on it came clean 111. that 336 is a continuous memory code

 

[FIND]

336 is DPFE sensor signal is/was was high

Doesn't necessarily mean you have a problem, just means that your DPFE sensor has recorded high pressure difference above or below the EGR.

If the relay is clicking, then the relay MAY be working correctly. Test for power coming off the relay. Just put a probe to the wires going to pins 3,4 and 5. They are the heavy gauge wires. The small gauge wires are the wires for the signal from the ignition switch to send power to the fuel pump.

Honestly though, if you have switched relays, and the truck started, you have already done all the troubleshooting you needed to do. You can assume the relay is bad or weak at this point and replace it with the relay you switched in or a new relay.

 

[YBCold]

my EEC relay was triggering my fuel pump. i think in the 91 atleast the two relays are connected or the EEC is in charge of the fuel pump. i just plucked out my EEC and smacked it and it seems to have fixed the issue atleast for now

 

[mgmgmg]

you mean your EEC power relay? what do you mean?

 

[YBCold]

yep EEC power relay i think it was the black one under the power distrobution box.

 

[mgmgmg]

ok heres what i did i bought a new eec and fuel pump relays and some contact spray and see what happens in the next couple of days? Wish me good luck!