90 5.0 runs fine then abruptly dies. Help??

[Mustang Kid]

My dad has a stock 1990 5.0 convertible that runs fine then abruptly dies and has done this several times. Then it won't start again for around half an hour. Anyone know what the problem could be? Thanks.

[Potentialmerc86]

Sounds similar to a problem I had on my 90 GT. My fuel pump relay was getting hot and caused it to die. Once it cooled back down, It would start fine. Once I changed the relay, it quit doing it.

[Mustang Kid]

Where would that relay be located? I'm a noob and my dad doesn't have the time

[wenkeracing]

Sounds like it may be the tfi module going bad in the distributor. When it gets warm it dies then when it cools off it will start again? That would my guess

[wenkeracing]

If it was the fuel pump relay it would have no fuel pressure then you wouldn't hear the fuel pump running or priming

[Mustang Kid]

Thanks, when we get the car out of storage I'll have to replace those things

[svo6]

TFI module!!!!!!

[Mustang Kid]

I know this is an old thread, but my dad had replaced the TFI and the car still had the same issue. He also swapped the Mass Air sensor with one off one of our other cars, and there was no change either.
Can anyone else shed some light on this?

[brianj]

Unfortunately, there are about a dozen expensive things that could cause this. You would probably be better off taking it to a garage than doing the "shot-gun" method of repair. Throwing non-returnable electronic parts at a problem gets real expensive really quickly.

[floodstang]

Maybe ignition coil. Also check the ignition switch on the steering colounm. The electrical part not the key cylinder. Ford had a problem with the switch seperating and it would lose contact and cause the car to kill. They had a recall on them several years ago.

[TWR2003]

stock 1990 5.0 convertible that runs fine then abruptly dies and has done this several times. Then it won't start again for around half an hour.

Runs fine for how long before it dies?

Can you pull a spark plug right after it dies to see if its wet or dry?

When it wont start have you checked for spark by pulling the coil wire from the distributor and placing it near a good ground and cranking the engine?

Have you tried to get EEC codes? (you do NOT need a fancy code reader)

There is a lot of diagnostics you can do for no cost. Or you can just guess and start replacing parts and drain your (or you dad's) wallet.

[DRAGTOP89]

Had this problem with my 89 5.8,f250,coolant temp sensor. Would not start,code. And. Ack as such. As soon as I put new one in,fired right up.

[kbrandt]

You really need to do some more diagnosis. I'd start with checking for spark when it's in the no-start state. I like to use a spare spark plug that is touching a good ground while hooked to one of the spark plug wires. Then have someone crank the engine. You should see a nice spark.

Let us know if the fuel pump is priming when you first turn the key to the run position. Most of the time, you can hear this from the driver's seat as long as there isn't too much background noise. If you don't hear it, have someone listen at the trunk when you turn the key.

[TheWizard]

Bad fuel pump, ignition coil, ignition starter switch, TFI module, tps, distributor pick up coil, vacuum leaks, etc.
These are all probable causes of the symptoms you described. You really need to run the codes.

[PIGBOY]

FONDLE THE CONNECTORS AT THE REAR BASE OF INTAKE MANIFOLD. WHERE THERE ARE THE HUGE CONNECTORS THAT ORIGINALLY ARE CONNECTED TO THE INTAKE WITH A LARGE PLASTIC CLIP. SOME TIMES THESE GET CORRODED INSIDE AS WELL AND IT IS A MAJOR POINT OF TUNING ERRORS. THIS IS ALSO A VERY COMMON PLACE TO CURE INJECTOR FIRING ISSUES. NOT LIKELY YOUR ISSUE BUT IT IS A SOURCE TO BE DEALT WITH AND ELIMINATE.

[Hissing Cobra]

All of this is good advice. My '89 LX 5.0/5-speed was doing this last year and it turned out to be the TFI module. When cold, the car would run fine but as soon as it warmed up, it would die. I've had no problems since. When your dad installed it, did he use the grease that came with it? That grease adsorbs the heat and helps to protect the module itself.

I hope you can find the problem. Good luck.

[eeprete]

Air, fuel, ignition... Diagnose each system independently to isolate the source of the problem.

Do some basics:
- scan the computer for codes
- check for spark
- check fuel pressure
- check vacuum
- check for airflow restriction both intake and exhaust