unlpuged inertia switch pump still runs w/key on

[dieselmech]

Hi I have a 91 explorer with a 4.0 and 123000 miles on my fuel pump runs all the time with the key in the on positon even with the fuel pump fuse pulled,the fuel pump relay unplug and the inertia switch unplug. It runs great I had to replaced the pressure regulator fuel was coming out the exhaust.I sure could use some more ideas.
Thanks Eric

 

[410Fortune]

somebody has hard wired in your pump to an ACC feed wire, most likely because they couldnt find any other way to fix the real problem (either a bad relay or wiring). I would check the continuitywires from the EEC to the power dist box and relay, to the inertia switch and then to the pump (one wire pink/black)

You can use a meter to do your checking, a pinout book will help a great deal, Also dont forget the computer sends a - signal to the relay........

 

[dieselmech]

I was going to check out the inertia I am sure both sides are going to be hot with it unplug I just didn't know where the feed from the ecm came in at I thought it would come in at the relay but did not know for sure thank you I live in northern Michigan our low was -12 alittle cold to work in if you have anyother ideas I would like to hear them
thanks again Eric

 

[410Fortune]

Eric:
Quick temp fix = put a switch on the PINK/black wire going down to the pump.

Real fix:

Trace the fuel pump feed from the EEC (dont know pin # off hand) to the relay. Make sure the signal is being sent from the EEC to the relay.

Check the fuel relay for + from bat, - from chasis, signal from EEC, and signal out (to inertia)

Then, jump the inertia switch wires (small jumper wire from blue/orange to pink/black, if I remember right...)

Then check the signal to the pump, via the pink/black wire (located under the brake booster, where it leaves the main harness and goes down along the drivers side frame rail, to the pump)

It goes:

From computer to relay under hood
From relay to inertia switch
from inertia to pump

 

[dieselmech]

I will check it all Thank you
YOU ARE THE MAN