I have a 94 F150 4.9L, Auto tranny. I have had igniton problems finally took it to the dealer and after about a week I got it back. The dealer changed the ICM and the truck has ran fine for about 1.5 months now, 90% of the time the engine turns over normal but will not start, I can pull the SPOUT (shorting plug) out and it will start. I reinstall the SPOUT and the RPMs increase and the truck runs great. I am wondering if the ICM has gone bad or if the problem is in the computer or distributor. I tried to do some checks using a Haynes manual today but of course it started fine everytime. Has any one ever heard of this?
94 F-150 Ignition troubles
Feb 16, 2004
3 Replies
You may have a bad coil or coil wire which cannot provide the juice when the timing is normal. Removing the spout connector retards the timing to the base position. Also, a bad coil or coil wire can cause the ICM to fail which you have already replaced. Just because the coil has a long enough spark does not mean it is OK. The spark should be nice and blue - not orange or red. If that is the problem, the ICM may be bad again.
It's easy if you have the scope but, as a DIY'er, the only thing you can do is judge it's color and spark length based on eyball experience since the engine does seem to run wiht it once it starts. E coils for the Ford can be found relatively cheap at $12 - $15US at places like Advance Auto up to around $100 at Pep Boys or a dealer. I would be tempted to throw a cheapie in there with a new coil wire just to see what happens. They are easy and quick to change with minimal tools. I have had several test OK but, wouldn't light the fire in the engine.
Good Luck!!
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required