95 5.0
Problem: When engine is warmed up, RPMs will drop 100-200 intermittently, resulting in a bad sputtering. Sometimes it will happen for 10-15 minutes, then go away again for a while...
First Diagnostic from my mechanic was distributor cap and rotor replacement. Seemed fine for a day, then problem started again.
Then I took it to a Ford Dealer, after almost a week and a $200 diagnostic fee, they determined it was the coil or the stator. They were "pretty confident" that it was the coil, and they would change it for $150, but if that did not work, the would try the stator for $200... They did not sound very confident, so I decided not to let them do any work. I changed the coil myself for $18, and it did not help.
Spark plugs and wire set (Summit brand) have about 2000 miles on them. Could this be the result of one of the wires breaking down when it's heated up? I did not keep the old set, so I can't try that without buying a new set.
Does anyone have any suggestions?
Thanks

 

Clean out your Throttle body, run some Fuel injection cleaner, and check your IAC


by the way smart move changing the pick up coil by yourself

 

The TFI modules don't last forever. I had 1 go on my Tempo. While I was driving, the motor just cut out like I turned the key off. Sometimes they go slowly and put out a weak orange spark. The local parts store around here tests them for nothing. Maybe the 1 around you does too. Check it out. Put some dielectric grease on it when you reassemble they new/old one to dissapate the heat.

BTW, you'll need to grind down the proper 1/4 drive deep socket to fit in there, or you can get the tool to remove it.

 

Thanks for your suggestions... I will try them out!
In the mean time, please continue to post any other ideas!!!

 

Yes as the wires get hot, it raises the resistance and can cause a miss. But it's not usually intermittant. How does it run when first started and how long does it take for the problem to start happening?

 

Is the TFI the same as the "ICM" located on the fender apron?
I don't see anything mounted to the distributor

 

It runs PERFECT for the first 8-12 minutes, then it starts acting up.

 

i had that problem with my red one, i fixed it when i changed the tb & iac, adjusted & adjusted it. on my white one when i first cranked the car it loped so bad it sounded like i had a huge cam in it, when the only thing was that i had a vac. leak.

 

Has to be electronic not mechanical. Something is getting hot and causing the problem.

 

It might be different with the later 5.0's. On mine it's mounted to the dist. Here's a cool short on how to replace it. There's a pic with the TFI installed at the bottom. http://www.turbotbird.com/techinfo/TFI-PIP/TFI-PIP.htm I did a search on Ford TFI's, and there was a class action suit against Ford because the TFI's were dying all over the place.

From what little I've read, they seem to act up with heat. 'Could be your problem. But like I said earlier, mine died instantly, so you're lucky you haven't been stranded like I was. Here's another quick link. http://autorepair.about.com/library/a/1h/bl926h.htm