87 F150 300 6 cyl bucking & stalling on highway

Recently bought the truck mentioned in the subject line. After about

10 miles of highway driving it started bucking and finally stalled. I managed to roll to the shoulder out of traffic. After about five minutes wondering what the problem could be I tried starting it again, and it fired right up.... only to go another 5 or so miles and buck/stall again. I made it home after three of these buck/stall events. No accidents, but a few scary moments.

Did some googling on "ford ignition problem" and found this to be a problem on many 80ish ford trucks caused by the TFI ignition module getting hot and failing.

Has anyone moved the TFI module away from the distributor to a cooler spot with good results?

Might moving it to a cooler spot and giving it additional heat-sink base solve the problem?

Is a new TFI module necessary?

If so, are they available through a regular auto parts store?

What about a new TFI module and moving it to a cooler spot with addl heat-sink.

thanks, george

Reply to
packrat
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Depending on what type of ignition module your truck has, this could also be the problem. My first car, which was a 1986 Tempo, had a Duraspark ignition module, which on its way out, displayed similar symtoms as to what you are describing. The 1984 F-150 that I just sold, also had the same type of ignition, and it too, was starting to display these symptons, but only on the highway around 100 km/h, or while the engine was under a load. The good news is that these modules can be purchased from sources other than the dealer, the one I priced for the F-150 was only $40 Canadian.

Hope this helps, Sharky

Reply to
Sharky

Replacing the ignition module is an easy fix, but you'll need a Ford distributor wrench from an auto parts store and the special high-temp grease to help keep the module from getting too hot. Not sure if you can move the module, it plugs directly into the distributor on the side, at least the ones I have seen. You'd have to solder some terminals to some properly guaged wire, etc., etc.

Reply to
sleepdog

Dont bother relocating.. bet you will see the problem when you take it off.

The only OEM TFI's that have failed on my fords have had caked/dried grease. The only aftermarket ones were back in the late 80's and were 'noname types.

Scrape off old add new, along with a module that doesnt list wells as the mfr.

Reply to
Backyard Mechanic

What's that grease called again, what brand? I'm looking to put my distributor back into my old Escort and I took the TFI off, still worked fine last time it ran, but while it is out and all... all the old stuff is cooked pretty dry. Was going to clean it up and put some new stuff on, there's a pep boys on my way home from work would they have something. I only buy sundries from that place, I think this qualifies.

Thanks

Reply to
sleepdog

Dielectric grease. Some parts stores also sell it as spark plug boot grease.

Sharky

Reply to
Sharky

Don't use dielectric grease for the mounting side of the TFI module! You need thermal grease (aka heat transfer grease). The dielectric grease can be used on the connector side of the module (to help waterproof the connector).

Ed

Reply to
C. E. White

Does the stuff you put on the back of brake pads qualify? That's the high-temp silicone grease used to quiet down the vibrations. I have some of that.

Thanks

Reply to
sleepdog

NO! You will fry the module if you use that suff. It is mostly for "gluing" the pads to the caliper to prevent squealing. If you can't find it at a parts store (a new module should come with the proper grease), go to a Computer Store and look for heat transfer grease (used between the CPU and CPU heatsink). Motorcraft refers to the stuff you need as Silicone Heat Transfer Compound, P/N XG-6 (or Ford Part Number ESF-M99G123-A ). References:

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(search the pdf for XG-6)
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Ed

Reply to
C. E. White

Hey thanks for the info and links, saves me a bunch of headache trying to describe to the "help" at pep boys what I'm looking for. Probably just get it from Rockauto.

Thanks!

Reply to
sleepdog

My bad! And to think, I'm a computer tech, so heatsink compound should have been my first answer.

Thanks for the correction Ed.

Sharky

Reply to
Sharky

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