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Engine 1990 GT suddenly dies while driving

  • Thread starter Thread starter RedFox90
  • Start date Start date Apr 15, 2022

RedFox90

New Member
Apr 15, 2022
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Clover, SC
Apr 15, 2022
#1
  • Apr 15, 2022
  • #1
I've recently ran into the problem of my 1990 foxbody dying while driving. It could be either in my neighborhood a few blocks from the house or the next time I take it out it won't die at all. It's very sporadic, but continuously happening. I've replaced the ignition switch and that didn't work. It doesn't seem fuel related as it just cuts off without any sputtering or anything like that. Once it dies I can turn the key back and crank it immediately again while coasting. It always starts right back up. I'm at a loss, as I've taken it to my mechanic and they can't figure out what's going on with it. They said they've checked the grounds and wiring and can't seem to find anything loose or out of the norm. I've read some posts it could be distributor, fuel pump, IAC,etc. I'm not sure if we've had other people with the same problems on here and diagnosed exactly the root cause with same issues? Any help would be greatly appreciated. Thanks!
 
M

Monkeybutt2000

Mustang Master
Aug 11, 2019
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Lafayette,IN
Apr 17, 2022
#2
  • Apr 17, 2022
  • #2
Sounds like the classic bad TFI module. You can test it yourself or take it to Autozone.
 
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alutwon

Member
Dec 10, 2020
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.
Apr 23, 2022
#3
  • Apr 23, 2022
  • #3
second on the TFI module, especially since it's intermittent. When you get a new one be sure to put thermal paste on the back where it meets the distributor so it won't over heat. Also the motorcraft units are the best, I had a cheapo part store one and it died in 2 years
 
Reactions: RedFox90

RedFox90

New Member
Apr 15, 2022
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0
1
Clover, SC
Apr 23, 2022
#4
  • Apr 23, 2022
  • #4
alutwon said:
second on the TFI module, especially since it's intermittent. When you get a new one be sure to put thermal paste on the back where it meets the distributor so it won't over heat. Also the motorcraft units are the best, I had a cheapo part store one and it died in 2 years
Click to expand...
Thank you!
Monkeybutt2000 said:
Sounds like the classic bad TFI module. You can test it yourself or take it to Autozone.
Click to expand...
thanks!
 

CAMTWO1070

Active Member
Dec 17, 2021
238
79
38
NY
May 7, 2022
#5
  • May 7, 2022
  • #5
I'm thinking that its more ignition switch issue related or a relay going fritzy..Sometimes they like to seperate into two halves and momentarily seperates when you hit a bump etc......

 
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JD1964

there is enough sticking out to grab on to
15 Year Member
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#6
  • May 7, 2022
  • #6
While you’re at it, check the capacitors on the ECU board to see they’re leaking oil and corroding the board. Very common on these cars. It can cause intermittent problems at first but will eventually result in a no start condition.
 
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jrichker

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#7
  • May 8, 2022
  • #7
Does the radio or blower motor for the A/C and heat quit at the same time?
If they do, the problem is in the ignition switch.

If not, the problem may be in the computer power relay or fuel pump relay.

TFI and PIP problems usually make you wait until they cool down before they will do a restart.
 

manicmechanic007

5 Year Member
Sep 26, 2017
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Roy, Utah
May 8, 2022
#8
  • May 8, 2022
  • #8
Next time it dies jump out and slap one of these on it
If it allows you to drive home your diagnosis is complete
 

manicmechanic007

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Sep 26, 2017
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Roy, Utah
May 8, 2022
#9
  • May 8, 2022
  • #9
 

manicmechanic007

5 Year Member
Sep 26, 2017
2,531
713
143
Roy, Utah
May 8, 2022
#10
  • May 8, 2022
  • #10
Most every Ford tech worth his salt has one of these in his toolbox
Here is a schematic for you to make one yourself out of wrecking yard parts
 

manicmechanic007

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#11
  • May 8, 2022
  • #11
 
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Mindseye007

5 Year Member
Oct 21, 2020
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131
63
ontario
Jun 22, 2026
#12
  • Jun 22, 2026
  • #12
RedFox90 said:
I've recently ran into the problem of my 1990 foxbody dying while driving. It could be either in my neighborhood a few blocks from the house or the next time I take it out it won't die at all. It's very sporadic, but continuously happening. I've replaced the ignition switch and that didn't work. It doesn't seem fuel related as it just cuts off without any sputtering or anything like that. Once it dies I can turn the key back and crank it immediately again while coasting. It always starts right back up. I'm at a loss, as I've taken it to my mechanic and they can't figure out what's going on with it. They said they've checked the grounds and wiring and can't seem to find anything loose or out of the norm. I've read some posts it could be distributor, fuel pump, IAC,etc. I'm not sure if we've had other people with the same problems on here and diagnosed exactly the root cause with same issues? Any help would be greatly appreciated. Thanks!
Click to expand...
Did you solve it?
 

CAMTWO1070

Active Member
Dec 17, 2021
238
79
38
NY
Jun 23, 2026
#13
  • Jun 23, 2026
  • #13
My money is on the relays either for the ECU or the fuelpump....

What most dont know is that inside a relay the voltage goes through a strip of copper that has a contact pad that gets tarnished over the years of turning on and off that diminishes voltage also to mention that electromechanical devices dont maintain their electromechanical strength throughout their lifetime and the slightest bump can cause the contacts to break free. momentarily because as you can see from the pics the electromechanical attraction has to fight the internal return spring.....



The relays I use in my F250 draw half the voltage to trigger and handle up to 300amps of voltage which works perfectly for my 170 amp G3 alternator upgrade.......I use them for my FP,ECU also cooling fans..........

 
Last edited: Jun 23, 2026

nickyb

I gotta say i never painted my nuts, Never Ever
15 Year Member
Apr 3, 2009
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153
nevada
Jun 23, 2026
#14
  • Jun 23, 2026
  • #14
Mindseye007 said:
Did you solve it?
Click to expand...



The op hasn't been seen since 5/22 ,he most likely fixed it and disappeared.
 
Reactions: Mindseye007 and Shakerhood

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,832
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183
Claremore, OK
Jun 23, 2026
#15
  • Jun 23, 2026
  • #15
So you are saying it was the old "fixed and to hell with telling you guys what I did" routine.
 
Reactions: Mindseye007 and Shakerhood

General karthief

wonder how much it would cost to ship you a pair
5 Year Member
Aug 25, 2016
27,875
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polk county florida
Jun 23, 2026
#16
  • Jun 23, 2026
  • #16
I'll bet most times they found something stupid or obvious that was missed.
Been there myself but I'll own up , you know I'll make a good story out of it.
 
Reactions: Mindseye007

nickyb

I gotta say i never painted my nuts, Never Ever
15 Year Member
Apr 3, 2009
2,979
1,626
153
nevada
Jun 24, 2026
#17
  • Jun 24, 2026
  • #17
More respect if ya own up.
 
Reactions: Mindseye007

General karthief

wonder how much it would cost to ship you a pair
5 Year Member
Aug 25, 2016
27,875
10,543
203
polk county florida
Jun 25, 2026
#18
  • Jun 25, 2026
  • #18
nickyb said:
More respect if ya own up.
Click to expand...
Humility and common sense is almost absent in society today,
The one thing I've learned over the years is most of the issues with our cars are self inflicted more often than not.
 
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