IF something (heat, coil, etc.) causes a TFI module to trip and stop the engine, is the TFI module no good any more?

My 2.9 keeps dying with no spark after warmup and I suspect the TFI. However, I have put two new TFI's on it and it keeps happening. I changed the coil and coil wire and still no luck. I changed the coil after the module failed and it failed again. If the original coil was to blame in the first place, do I now have to get yet another new TFI or is the most recent one still good?

This electrical stuff is driving me nuts!

Thanks!

 

I'm no expert, but here's my experience with a 90 B2 2.9L...

The TFI left me stranded twice on hot days in traffic. I replaced it. About a week later, I got stranded again on a hot day - same thing, no spark. After cooling off for 30 minutes or so, I started it up and drove home.

After doing some research online, I pulled and dismantled the distributor, changing the stator (connected to the TFI) in the process. I also put in a second new TFI module. I've been carrying the first new TFI as a spare for over 2 years and 50k miles now, and have never needed it. This may or may not be similar to your problem.

Two things to consider -
1) I've since read that you can buy a new distributor (complete with stator) for not much more than what a stator will cost. If there's a lot of crud built up on the distributor shaft (oil varnish, basically), you may not be able to get the distributor apart. If you do pull the distributor, do so very carefully and re-install very carefully to be sure everything goes back EXACTLY as it was.

2) I decided that if things were getting hot enough to fry the TFI on my B2, I should try to cool it off. I installed a 180 degree thermostat for the short term, and later installed a bigger radiator (4.0L AT for Explorer) and put the 195 T-stat back in. Make sure you're not overheating for some reason. If so, then you'll soon be worrying about more than TFI modules.

 

It may be the dist/stator and I might go that route. I'll check out new ones and see what it's going to run me.
I don't think it's getting too hot as far as the cooling system goes. I've been driving it here in FL for years now and it just doing this started in this 70 degree winter weather.
The temp guage is staying well below center.
Thanks for the idea!

 

SUCCESS!!! At least for the last two days.
I replaced the distributor, $59. Runs great, no dying even after hours of continuous running at idle, in traffic, on the highway.
With a little more planning, they probably could have made access to the distributor a little more dificult.
Thanks!!!

 

As much as I love Fords, they have had two problems which seem to contribute to one another. Ford has always wanted their engines operated quite warm in order to reduce emissions. The TFI module is VERY susceptible to heat. The engine runs hot enough to cook the module. The module cools back off and it will operate just fine--until the heating/cooling cycles ruin the internal circuitry of the module. Do you recall the big lawsuit Ford has over the TFI modules and their vehicles dying or stumbling? One key to keeping a TFI module cooler and running better and longer is to ALWAYS coat the distributor side of the module with heat shrink/dielectric compound. Too, a few of the TFI modules seemed to have had a problem with the screws securing it to the distributor body working loose as the truck was run. Believe it or not, that can contribute to a small degree to the stator going bad. I knew a fellow who continually was having his TFI ignition go down on him. He just "knew" he was getting bad parts. But, he wasn't tightening the screws correctly and ensuring they remained torqued and it was ruining his primary ignition circuit.