The car warms up, the rpm drop happens (only 100 rpm). When in Park or Neutral the tick is hardly noticable. So heat on the ICM causing the tick? Checked for arcing plug wire in the dark but did not see any sparks. Coil is new. Thanks.

 

I thought ICMs either work or don't work.

 

Thanks for reply Shoebox. What else could it be then?

 

I know the experts in here have some idea of what is going on right??

 

Idle Air Control Valve??????

 

That's probably the problem and needs to be replaced anyway after 102k miles. Where can you buy just the IAC valve by itself or can you?

 

Local parts store...

Had to order mine..

 

From my horrible experiences with ICM's. They work just fine, then all of a sudden don't. All of mine have worked good until the vehicle has reached operating temperature. Then it just died. Cooled down, started back like nothing.

 

Yes, that is my experience with ICMs! They can be very frustrating to track down due to their intermittent behavior. But the above post accurately describes the 'finger print' for a moribund ICM.

I'll bet 1FstFormulaV8 had the same experience with Ford's P.O.S ICMs that I had with my 90 SHO. They were so bad that Ford had a recall on them!

 

Not to highjack the thread, Don 97 SS. I actually destroyed mine when I broke the motor mounts. I replaced it's ICM, but still without a good motor mount. She's sitting.


If it is the ICM, when you change it DISCONNECT the battery! I didn't do that once and it blew my ignition fuse. Though it was the ICM that had gone bad, the blown fuse had me looking elsewhere.

 

Or pull the ignition fuse

 

Hopefully, they are not still waiting for advice after 4 months.

 

That was the symptoms of mine last summer. Took me a month to figure it out. Car would start and run fine until engine got good and heat-soaked. Then it would pop the 10A ignition fuse. Then I had to get towed home twice in one day. That sucked.