But if i'm using an 89 TFI module with an 89 distributor and an 89 computer, shouldn't that all work together. Do I need to get an 89 coil?

 

Read post #14...

I don't wish to argue with Bill K, but the parts catalog only lists one dizzy mounted module for 1984-89 F150/350; Econoline 150/350 and Bronco (U150)..

Parts catalog says: E73Z-12029-A Coil fits all 1987/89 E-F-150/350 & U150

 

Ok, so it shouldn't matter what TFI module I use. My question is, what could be killing them. Let's take heat out of the equation because it died within 5 minutes of a cold start, therefore, heat is not the issue.

If I understand correctly, the TFI module and ignition coil receive power from the ignition switch. The TFI module then supplies power to the PIP (Stator) in the distributor, which then sends a signal back through the TFI to the EEC-IV to determine spark timing. This signal then goes back to the TFI module which then tells the coil when to fire. With this in mind, it seems like the only things that could be killing the TFI modules are the stator or the coil. Or, I just got two faulty TFI modules. Any input on this? Thanks!

 

I always though they were all the same for those years except the remote mounted ones but I know from the Ford Shop manuals that there are seven different Ignition systems used (Two of the systems are distributor mounted, A & E) with the "E" being for newer trucks and does not use the start wire.
I do know that the TFI modules that the Auto Parts stores sells will not work a lot of times.
We had one guy on here that replaced the TFI four times and the engine would run I think but not right and then he went to Ford and got one and it cured his problems.

 

Yeah, they probably sold me some poop in a box, but hey "its got a warranty". Just once, I'd like to buy something and it work the first time....

 

Maybe but I do not know what year they changed the Distributor mounted TFI Module.
The Old one had Start input and newer CCD TFI Module used the same pin for the IDM output. Both were Distributor mounted TFI Module.
So the Computer has to match the TFI-IV Module.

Here is a diagram of both systems:

 

That was my thinking also, bad Ignition Coil, PIP Sensor or wrong/bad TFI Module.
The 87 would have had the System A and if they sold you a Distributor with the newer System E maybe the start wire would take the newer TFI Module out.

 

replace the stator, prob the cheapest part on the truck, replaced mine and my truck now runs great, cus i replaced every sensor before getting to the stator.

 

I got a new stator with the new distributor 5 days ago. I have since been through 2 TFI modules. I think the stator or coil may be killing off my TFI modules, so I'm going to have the parts place swap out the new distributor for another one, (under warranty), and replace the coil while I'm under the hood. I'll let y'all know what I find. Thanks for all the input!

Aaron

 

Any update on this? I’ve got a similar issue with repeat failures.

 

there was a similar thread of this subject that popped up about a month ago. I believe the solution was non-counterfeit OEM module from the junkyard.

 

*Keep one of these in the glovebox for those old ones
I get 3 Motorcraft modules at a time at the junkyard
If you examine the inside circuitry of your bad ones, you may find a bubble in the thick film
That's where they get hot and burn the ground side power circuit out
So, when I go looking at the junkyard, I can tell the possibly bad ones
Usually, I can find a couple that look like they have been replaced before, and I get those ones

You can get home using one of these failed module bypasses

 

I feel like I have seen suggestions about Arctic MX-4 thermal paste being used on the back of these modules.

 

Yes, any thermal heat paste will work, what you get from the big parts store is, dielectric grease...with the modules, and they die a slow death, unless your in the heat (states) then its even quicker.