1990 F150 302 no spark sometimes. Help?

My 1990 F150 5.0 4x4 (110K Miles) has this annoying habit of losing all spark and either not starting or stalling in traffic. I pulled the coil wire from the dist and I get no spark. Where do I begin to diagnose this problem?? Are there any common items for this generation of F150 to start with? I don't know if its linked or not, but sometimes I get a really low/rough idle. I am thinking that the no spark syndrome and the intermittent poor idle are related.

Any ideas?

TIA

Reply to
DjE
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On Mon, 20 Jun 2005 03:10:59 -0500, DjE rearranged some electrons to form:

TFI module

Reply to
David M

It's mounted on the side of the distributor. When you replace it be sure to use the thermal grease.

Al

Reply to
Big Al

As has been stated, it is probably the TFI module on the distributor if it always happens when warm. Make sure you use thermal grease or paste - not dielectric grease. Some folks think it is the same thing. It is not.

Good luck Lugnut

Reply to
lugnut

I took the old TFI unit off and had it tested at the local parts place. It came up bad. I have driven around all day in 90+ heat with no stalling now so I think its all better. Instead of using their dialectric heat sink grease, I use some of my Arctic Silver heat sink compound. That will allow better heat transfer to the distributor until I relocate the module when I pull the dist out to replace the hall-effect sensor later this week.

Thanks for the help all!

Reply to
invalid unparseable

Did you replace the coil and distributor with a new one? Try all new spark plug wires as well. The truck is fifteen years old so it is time for parts to start to fail on you.

Reply to
Art Vandolay

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