91 fox fp issue

91foxbod50

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Sep 26, 2007
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My 91 GT has a issue, the fuel pump does not prime when ignition is turned on. Their is no spark comeing from the ignition coil. Whats the main causes for this? The car ran fine a month ago when i left for texas. It has been sitting since then.
 
Do you hear any of the other systems make noise (odd buzzing and what-not)? If not, see if you have EEC relay output (you can do this by testing for accessory 12 volts at the coil, an injector, etc). If you're missing it, check the wiring at the solenoid. A packrat might have chewed something or corrosion might have set in.

See Jrichker's Cranks But No-Start checklist in the Useful Thread Sticky.

Good luck.
 
Possible causes are a bad fuel pump relay and/or a bad EEC relay. I think that the EEC relay powers up the fuel pump relay. I believe the fuel pump relay can be found under the drivers seat, and the EEC relay is behind the glove box. If I am wrong I am sure someone who knows will correct me on this point.
 
theirs no spark to the ign coil while cranking, but when done cranking their is a spark. their is no power going to the fuel pump or inertia switch. the relay under the seat turns on. i felt it click, is their any fuses on the fuse box under the dash that has anything to do w/ the fuel pump? would the computer have anything to do with it? what does the eec relay look like? behind glovebox? is it easy to access. i can hear the pump kinda poof out when turned on, its not fully primeing.
 
Not having spark till letting off of the key (going from Crank to Run) suggests a TFI module issue or an issue with the wiring to the TFI (there's a wire for cranking vs running).
If you have the FP relay energizing but no power to the pump, check the pump's ground if necessary. Check the output from the FP relay (should be dk grn/yellow). If you have it, check it going into the inertia switch (the switch isnt tripped?) and out of the switch. Lastly, check it into and out of the FP electrical connector.

The EEC and circuit protection both play into the FP circuit. If the FP relay energizes, the EEC is exciting the relay. If you have load power into the FP relay (pink/blk wire), then the circuit protection should be ok.

The EEC relay is a pain to access. And if you hear your FP relay actually energize, the EEC relay is working.
 
I found some mouse hair in my car last night. So I started to investigate. I couldnt find any frayed wires so i took the battery tray off and i did run into a problem. Most wires under the battery tray were pinched off. Do any of the fp wires run under the battery tray?

I checked it going to the switch, when it was tripped and just off. No power what so ever going to the enertia switch.
 
i changed out the tfi module, and their is power going to it. Their is still no power going to the fuel pump and checked the connection their is still no juice. theirs power under the hood for the fuel pump fusible link. Their is one wire behind the engine block that is hanging out, it is orange i cant find anything it goes to. i looked on my friends lx and his runs into his harness. but the wire the comes out of the harness looks like it grounds on a bolt to the intake.
 
The orange wire you see hanging out is probably your HEGO ground.

I would do systematic testing to determine what has failed. Randomly tossing parts at the problem only introduces more variables.

You have to be specific when you talk about items having power. For example, a TFI module has several power sources going to it, and it's final output is a ground signal, not a 12 V reference.

See Jrichker's Cranks But No-Start Checklist in the Useful Tech sticky.
Run the list in order and you'll find the issue with a minimum of time and expense.

Good luck.