Strange ignition problem

[71Torino]

My wife's 93 Bronco (351) would not start the other day. I wanted to check the codes but I could not get any response from the code reader. I did hear the relays click as they should upon starting the test but then I kept hearing what I first thought was a relay. It turned out to be the ignition coil constantly firing. I disconected the coil to distributor wire, then turn the key to the on position, The coil constantly fires to ground even though the engine is not turning. I thought the ignition control module would need a sensor input to fire. I replaced the ICM. The problem still exists. Any ideas?

 

[snowman74]

Starter maybe?

 

[wtfdissux]

would like to hear the end on this one my truck does that every once in a great while ussually burning the end right off the wire so gotta drive around with spare coil and wires in truck

knock on wood its been a while

 

[firelt90bronco]

Starter solenoid, starter, wiring, flywheel

 

[wtfdissux]

flywheel???

 

[snowman74]

flywheel???

If there are teeth missing on flywheel, or it's not aligned properly with starter, it could very well be the flywheel.

Snowman74 >-

 

[wtfdissux]

I understand that but how would that cause the coil to fire constantly?

 

[snowman74]

I understand that but how would that cause the coil to fire constantly?

Hmmm, good question. I don't know if the flywheel has to be turning in order for the coil to fire or not. Would somebody who knows please educate me?

Snowman74

 

[miesk5]

My wife's 93 Bronco (351) would not start the other day. I wanted to check the codes but I could not get any response from the code reader. I did hear the relays click as they should upon starting the test but then I kept hearing what I first thought was a relay. It turned out to be the ignition coil constantly firing. I disconected the coil to distributor wire, then turn the key to the on position, The coil constantly fires to ground even though the engine is not turning. I thought the ignition control module would need a sensor input to fire. I replaced the ICM. The problem still exists. Any ideas?

"I wanted to check the codes but I could not get any response from the code reader"

do you have a CEL?

try the non-code reader self-test by Ryan;

http://fordfuelinjection.com/?p=13

 

[snowman74]

"I wanted to check the codes but I could not get any response from the code reader"

do you have a CEL?

try the non-code reader self-test by Ryan;

http://fordfuelinjection.com/?p=13

Al,

Does the flywheel have to be turning in order for the coil to fire?

Snowman74 >-

 

[wtfdissux]

was thinking about it and i don't agree that the fly wheel is a possibility as the engine is comp controlled not like traditional coil and distributor in the set up used the computer tells the coil when to fire whereas the flywheel really is only there to turn the engine when engaged by the starter

 

[miesk5]

The code check will narrow it down, then we can troubleshoot the likely culprits

 

[BLADE262US]

Reguardless of wether it is computer controlled or old points style 2 stroke or 4 stroke 1 cylinder or 12 something tells the coil to fire just before the piston gets to top dead center it has too or it wouldnt run . The 93 has an EECIV computer in it with a TFI distributor might have the module on the distributor or may be a remote mount one on the drives inner fender well either way the EEC gets its signal of when to fire from the distributor . If you take the cap off and the rotor you will see like a metal umbrella with slots cut in it there will be 8 windows and one is narrower than the rest this one designates number one cylinder to the EEC because the pulse it gets from the PIP will be shorter than the rest . Heres some stuff to read that I found while looking around . I would check that PIP sensor maybe has something in front of it a small piece of metal also check all the ground wires around the distributor .

http://www.asashop.org/autoinc/dec2002/techtotech.cfm

http://zenseeker.net/4x4/eec_iv_2_digit_codes.htm

/emoticons/[email protected] 2x" width="20" height="20" />

 

[wtfdissux]

feeling kinda stupid to dwell on this but am i correct in saying that the flywheel cannot be the cause?

 

[BLADE262US]

Naaaa dont feel stupid no the flywheel cant cause that the ignition system doesnt know that the starter motor is spinning so that wouldnt trigger the spark the crank must be turning in order for a signal to be generated from whatever sensor it has . Now if the sensor was bad or loosing ground somewhere that would be a better bet but if the motor doesnt roll over then there will be no signal to the EEC to generate the spark . /emoticons/[email protected] 2x" width="20" height="20" />