1985 3.8 Mustang convertible ignition problems

[Richard K]

Dear forum members,

I'm happy that I found this forum dedicated to the most unpraised Mustang with the most unwanted engine. It's all about the V8s, and very little about the 3.8 V6 so I'm happy there is at least one place on the internet that's dedicated to the Essex V6.

I'm from the Netherlands and my father has an Oxford white 85 LX convertible, originally sold in Hollywood but somehow it found its way to the Netherlands. He owns it since 1997 and uses it only in summer time for cruising with the top down.

It has proven to be quite reliable and we have managed to keep it going despite the complete lack of parts availability in the Netherlands. However, since a few years it seems to have developed a bad attitude that we haven't been able to fix yet.

It would start and run but the engine would sometimes just cut out while driving. When this happened, the car wouldn't start immediately and we sometimes had to wait for hours before it would start again. We fixed this issue by relocating the TFI sensor to the side of the engine bay, using the kit developed by McCully Racing Motors. We also replaced this sensor by a new one. The big change this has made is that the engine would cut out less often and more importantly would restart directly even if it did. We also replaced the oxygen sensors, without any improvements.

We took the car to a Mustang specialist who tried to read out any error codes, however without any clear result. The fuel supply and spark seem to be OK, we think there is something wrong with the ignition system, that shuts down the engine while driving. We have a wiring diagram and a basic understanding of the ignition system, but honestly speaking no idea what to do next. Hence, the reason for posting here. Hopefully you the enthusiasts on this forum, can help us with some advise, based on expertise, experience and failure of course.

Any tips or ideas are really appreciated (but please don't just advice us to swap it for a V!

Thanks in advance,
Richard

[webestang]

Had the same problem with my 85 2.3. I also used a relocate for the TFI. BUT.....and this is a big BUT I used an aftermarket TFI, it failed even on the remote unit with the heat absorbing grease. Went to a Ford Motocraft TFI and it has been fine ever since. Rockauto.com has them for around $80.
And when my 88 5.0 TFI failed I went straight to the Motorcraft unit and it's been fine.

[1984GTTurboVert]

Sounds like the PIP sensor(inside the distributor) is going, particularly regarding the cooling down part. Failure usually shows the same symptoms as failing TFI module and doesnt always show codes when pulling them.
A cheap part costwise but requires taking the distributor apart to replace so most just buy a remanned distributor. Not a daunting task to do yourself if you have a pin punch set for removing the distributor gear.

[webestang]

Sounds like the PIP sensor(inside the distributor) is going, particularly regarding the cooling down part. Failure usually shows the same symptoms as failing TFI module and doesnt always show codes when pulling them.
A cheap part costwise but requires taking the distributor apart to replace so most just buy a remanned distributor. Not a daunting task to do yourself if you have a pin punch set for removing the distributor gear.

I forgot about that PIP. I did replace the dizzy with new on my 2.3 for that reason.

[1984GTTurboVert]

I just rebuilt and replaced the PIP on my 2.3 turbo but years ago i had to replace it on my 3.8 tbird since i couldnt afford a whole distributor at like 150+ vs 18 bucks for just the sensor.

[KevinVarnes]

I agree with the PIP diagnosis. I had a similar issue a few years ago where the car would just shut down after driving for a while. It would usually restart after 15-20 minutes. Being on the road I didn't have much to work with, but a new (aftermarket) TFI module and coil did not resolve it. I wound up replacing the distributor (new PIP) and it has been fine since.

[gmatt]

My LTD with the 3.8 had these symptoms. Junkyard distributor fixed it, but I got a new one also as a spare(Ford NOS). TFI is still on the distributor. Haven't had any issues at all since replacing it.