91 escort that stumped mechanics


james33711
07-24-2010, 12:42 PM
I have this 1991 ford escort that I am using in an upcoming demolition derby. I had taken the fuel pump and wired it to a swich that I wired to the battery. Then I grounded out the other part of the switch. I did this in order to bypass the inertia fuel cut off switch. This somehow caused my injecters to stop being grounded out and not allowing them to fire. my pump works fine and there is pressure on the rail. The engine cranks over, and all of the fuses are good. but for some reason the injectors just wont open up and allow the engine to start. can anyone think of a reason for this happening.
btw its a 1991 ford escort wagon with a 1.9L 4 cylinder in it.

mcmalloy
07-24-2010, 01:49 PM
Hot wire the distribter , should fire up

denisond3
07-25-2010, 01:09 PM
A 91 Escort with a 1.9L uses a coil pack, doesnt have a distributor, and the signal to the coil pack comes from the EDIS 'igniter' and the PCM.

You may need to hook up the wiring the way it was originally to find if the injectors will fire. I dont know that the fuel cutoff switch is a simple open-shut type of switch, since when it trips to 'open' the PCM knows about it, and turns on a light on the lower line of the instrument cluster saying "fuel cutoff". I dont understand 'grounding the other part of the switch' - what switch?
I believe the engine has to see the signal from both the crankshaft position sensor, and the cam position sensor for the injectors to fire. There may be other requirements before it fires injectors (like a signal from the TPS or MAF), I dont know.

AzTumbleweed
07-26-2010, 08:34 AM
I would hook it all back up the way it was and then cut the wires at the cut-off switch and splice them together.

denisond3
07-26-2010, 05:30 PM
Arent there three wires at that 'inertia switch'. When it flips to 'open' for the fuel pump, it has also switched to 'connected' for a line going to the 'passive restraint system'. I have no idea what that does though.

AzTumbleweed
07-27-2010, 08:55 AM
Arent there three wires at that 'inertia switch'. When it flips to 'open' for the fuel pump, it has also switched to 'connected' for a line going to the 'passive restraint system'. I have no idea what that does though.

During a violent accident if a door opened then the 'passive restraint' (automatic shoulder harness) would release. You don't want that happening in the middle of a wreck. Since the fuel cut-off should actuate in a wreck it is designed to kill the restraint circuit. This stops the shoulder harness from releasing in the middle of a wreck!

zzyzzx2
07-27-2010, 10:46 AM
I have this 1991 ford escort that I am using in an upcoming demolition derby.

Poor Escort
:frown:

denisond3
07-27-2010, 09:39 PM
tumbleweed: Thanks for the insight. I havent messed with my 'inertia switch', but have had it activate once after going over a heat-bump on a macadam road.

Jamesjjr9110
06-19-2011, 01:11 PM
If I remember correctly if you unplug the fan relay the injectors wont fire. You tamper with the fan relay?

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