Fox Wifes 1993 LX 5.0 dies after replacing ignition parts

[Warhorse85]

Hello everyone, I'm having trouble figuring out why my wifes 1993 LX 5.0 dies while idling after replacing some ignition parts. The parts I have replaced are the MAF, TFI module and ignition coil. EGR was replaced last year. Car starts and runs great but after idling for a bit it surges for a couple of seconds then goes back to idling normal then about 5-10 seconds later it just dies as if someone turned the ignition key off. It will instantly restart and idle with no issue for a few minutes and do the exact same thing. I did notice that there is a loud buzzing noise coming from the EGR area while it's idling. Any help would be greatly appreciated.

 

[gkomo]

What TFI module did you use and did you use thermal grease in the mating surface?

 

[Warhorse85]

What TFI module did you use and did you use thermal grease in the mating surface?

Motorcraft and no I did not use thermal grease

 

[KRUISR]

Fuel pressure regulator sticking or not cycling right?

 

[Warhorse85]

Fuel pressure regulator sticking or not cycling right?

No clue, no idea how to check. Definitely not a fuel issue

 

[gkomo]

Motorcraft and no I did not use thermal grease

TFI could be getting too hot or something and causing issues… I believe they need thermal grease on the mating surface.

 

[slow84lx]

Just curious, why did you change these parts? Were you trying to resolve a problem? Do you still have the parts that you took off?

My first thought is to put the TFI that you took off back on and see if that solves the current problem.

 

[limp]

OH man, I bet you are on the $hit list at home

 

[AeroCoupe]

@Noobz347 - can you merge this thread with the one over in the Fox 5.0 tech forum?

 

[Noobz347]

@Noobz347 - can you merge this thread with the one over in the Fox 5.0 tech forum?

I'll close this one since the merge will make a mess.

W

Thread '1993 LX 5.0 dies after ignition parts replacement'

Aug 16, 2025

Hello everyone, I'm having trouble figuring out why my wifes 1993 LX 5.0 dies while idling after replacing some ignition parts. The parts I have replaced are the MAF, TFI module and ignition coil. EGR was replaced last year. Car starts and runs great but after idling for a bit it surges for a couple of seconds then goes back to idling normal then about 5-10 seconds later it just dies as if someone turned the ignition key off. It will instantly restart and idle with no issue for a few minutes and do the exact same thing. I did notice that there is a loud buzzing noise coming from the EGR...

• Warhorse85