no spark no start

[swamprat]

1994 4.0 would not start and had no spark. was getting fuel. Un-hooked battery for about 30 mins and hooked it back up and truck started. It stalled idleing and would not restart. Did the battery thing again and started right up. Turned off truck and restarted it. I don't know where I saw the suggestion about unhooking battery, just that it resets the computer to default. What is making it not start? Bad ICM or crank sensor. Or could it just be a ground issue that gets fixewd by messing with the ground on the battery?

 

[94RoadkillRanger]

You can bring the ICM in to a parts store to have it tested - free.
The crank sensor has no integrated circuit that would overheat but the connection could have corrosion.

 

[swamprat]

Didnt know that a part store would be able to check ICM. After more searching on line it looks like the crank sensor or its connection could be at fault. Relatively a cheap part to switch out. If the ice melts off this weekend I'll pull it in the shop at work and pull the ICM off and have it checked.

 

[RonD]

After engine stalls out, Crank engine and check a spark plug, if it is wet with fuel then ICM(EDIS-6) and crank position sensor are fine.
Check coil power, and if possible ohm out the coil, Google:how to check ford coil pack the easy way
Good easy to follow video.

EDIS-6 module on my '94 4.0l is by the battery on Rad support, BUT on the front side of the rad support.
Coil and EDIS-6 are powered by the EEC relay circuit

EDIS wiring Diagram here: http://www.useasydocs.com/details/EDIS.htm
scroll down to EDIS-6 diagram
VR sensor is the crank position sensor, so only the EDIS module sees this sensor.

PIP and SAW wires are hooked to the computer so it can time the fuel injectors based on VR sensor pulses, so if there was no PIP/SAW then there would be no fuel on spark plugs, computer wouldn't even know you were cranking the engine.

Because disconnecting the ground restores spark for a short while, yes, you could have a bad ground, check the rad support grounds, EDIS should be grounded there and it grounds the 3 coils in the coil pack

 

[94RoadkillRanger]

I'm sorry, I said ICM but was thinking DIS (which can be checked at a parts store.)