2001 GT wil not start when engine at operating temp. - MustangForums.com



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Old 01-29-2013, 09:30 AM   #1
Tyr
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Default 2001 GT wil not start when engine at operating temp.

I have a 2001 GT. It starts and runs fine when the engine is cold. When the engine reaches operating temperature, it shuts off. It doesn't spit, cough, sputter, etc. it just shuts off like the key has been turned to the off position. The engine will still crank at this point but will not fire and I can hear the fuel pump cycle when I turn the key. Once the engine cools off a bit it will start/run with no issues until the engine reaches operating temperature and then the engine shuts off again. There is no check engine light on and no codes. I am assuming the issue is being caused by a faulty relay/switch or something else of that nature.

Ladies and gentlemen, your thought please.
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Old 01-29-2013, 10:56 AM   #2
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What if any engine mods do you have?
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Old 01-29-2013, 11:25 AM   #3
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JLT CAI, 70mm throttle body, matching upper plenum, pypes cat back
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Old 01-29-2013, 11:33 AM   #4
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I'm not trying to do 20 questions so bear with me--I am trying to think of the things that might cause that. Does the engine temperature gauge operate as it should? Does your code scanner check for pending codes?
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Old 01-29-2013, 11:41 AM   #5
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I think the gauge operates as it should. Engine doesn't "smell" hot and it isn't leaking coolant if that is what you are getting at. I don't have a code scanner, I was assuming (from what I have read on the forums) that a code would appear in the odometer area. And I don't mind the twenty questions.
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Old 01-29-2013, 12:23 PM   #6
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I was wondering if the ECT sensor was bad, never telling the engine it was hot. The PCM enrichens the mix when cold, if that state remained when the got hot is could stall.

Let me think on it some more...
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Old 01-29-2013, 12:36 PM   #7
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Additionally, when I stated the car the other day I heard a singing noise like bearing (coming from the front of the engine compartment) or belt squeel. I don't this has anything to do with the stalling issue but it was something I noticed.

If the PCM richens the air/fuel mixture when the engine is cold wouldn't the motor still attempt to fire because it is still getting fuel, air, and spark. This acts like the engine is not getting any fuel and/or spark.

Is there a common relay/sending unit or switch for the coil packs? Even if I can hear the fuel pump cycle when the key is turned does this mean the engine is getting fuel?
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Old 01-29-2013, 12:41 PM   #8
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I assume the ECT is a failsafe to keep someone from running the car when the motor is too hot? Would this shut the car down if the coolant was too low?
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Old 01-29-2013, 12:54 PM   #9
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Quote:
Originally Posted by Tyr View Post
Additionally, when I stated the car the other day I heard a singing noise like bearing (coming from the front of the engine compartment) or belt squeel. I don't this has anything to do with the stalling issue but it was something I noticed.

If the PCM richens the air/fuel mixture when the engine is cold wouldn't the motor still attempt to fire because it is still getting fuel, air, and spark. This acts like the engine is not getting any fuel and/or spark.
Yes, it should just run rough, I was trying to think of things that might cause the problem.

Quote:

Is there a common relay/sending unit or switch for the coil packs? Even if I can hear the fuel pump cycle when the key is turned does this mean the engine is getting fuel?
The COPs are powered through the PCM relay (in the CCRM) via the same fuse (fuse #26, 30A, in the battery junction box) that powers the PCM, they are switched to ground for charging by individual MOSFETs in the PCM.

Maybe (long shot here) that fuse has some thermal issue?

If the fuel pump is running there should be pressure at the fuel rails, the PCM activate the injectors, again through MOSFETs. They all receive +12 V from fuse #2, 20 A, in the central junction box and are switched to ground by the transistor drivers.

Wouldn't hurt to check that either...
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Old 01-29-2013, 01:07 PM   #10
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Quote:
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I assume the ECT is a failsafe to keep someone from running the car when the motor is too hot? Would this shut the car down if the coolant was too low?
Not on the V8 engines. On the 6-bangers there is a cylinder temperature (CHT) sensor used for what Ford calls the Fail-safe Cooling Strategy. In fail-safe mode the PCM disables fuel injectors in a alternating sequence to reduce engine power and therefore generated heat as well.

The coolant level sensor was deleted during the 2001 model year...

Last edited by cliffyk; 01-29-2013 at 01:10 PM.
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