Fuel Pump Shutdown

helix1990 · 07-28-2009, 05:26 PM

I have a 1995 Escort GT 1.8L. The car shut down on me while I was driving and it wouldn't start again (the starter was working, but the engine wasn't catching). Once I got the car home, I checked to see if the car was getting fuel from the filter and there was no pressure what so ever. Next, I checked the fuel cut-off switch (inertia switch) and it was not tripped and it was working properly. After removing the rear seat, I examined the in-line fuses to the fuel pump and they were OK. When the key was turned to the ON position, the pump didn't make a sound. I tried to check the voltage from the fuel pump harness and what I got was over 8 volts. I bench tested the pump outside of the vehicle to a 12 volt source and it seemed to work fine. Later, I swapped out the fuel pump relay and, again, nothing happened. I even disconnected the battery for over 5 minutes to clear the engine management system and no success. I checked all the fuses associated with the fuel pump and injection system and they were all intacted. I need to know what else I need to check in the car. Do I have a engine management problem?

mark v · 07-28-2009, 05:42 PM

Check the grounds going to the fuel system.

helix1990 · 07-29-2009, 08:38 PM

The grounds going to the fuel pump seem to be fine.

taz4x4150 · 07-29-2009, 09:34 PM

Quote:

Originally Posted by helix1990

The grounds going to the fuel pump seem to be fine.

They "seem to be fine"
Did you take them off, inspect them, clean them, put them back on nice and tight?
I agree with mark v, that it sounds like a ground if you have voltage, but it's less than 12

BroncoJoe19 · 07-30-2009, 02:52 AM

I agree with both of these gentlemen, unfortunately it seems that none of us have a specific diagram for your year car, and can't tell you exactly WHICH ground is your fuel pump ground. Many times in fords it is one of the upper radiator support grounds.

Check teh fat battery cables, at both ends, and even the connectors themselves to the cables, clean and tight. Then the little grounds wherever you may find them. If all else fails try running a separate ground to the pump.

helix1990 · 08-04-2009, 09:13 PM

Thanks for all of your guy's input. As it turned out, the ground was NOT the problem. I was able to obtain copies of the schematics for my car from a local Ford dealer. With the help of an electrian I know, we poured over the schematics trying to find something that's a miss. I thought I checked all the fuses associated with the engine under the dash, except I missed one and it was the engine fuse. After replacing it, it blew again which indicated a short. We thought it might have something to do with the PCM power relay gone bad across the coil. After looking at the schematics again, we also had the cooling fan and the oxygen sensor on the same circuit as with the PCM power relay. Just by luck, with the ohm meter reading off the fuse panel from where the fuse blown, I wiggled the leads from the oxygen sensor and the meter showed various and erroneous readings. The insulation at the back end of the sensor was completely disintegrated which caused the short. After replacing the oxygen sensor, the headache was over. The car fired right up! I never thought a shorted oxygen sensor would prevent the PCM from getting any power and to send power to the fuel pump until now. Thanks again for your help, guys!