2001 GT wil not start when engine at operating temp. - Page 2 - MustangForums.com



4.6L (1996-2004 Modular) Mustang Technical discussions on 1996-2004 4.6 Liter Modular Motors (2V and 4V) within.

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Old 01-29-2013, 01:19 PM   #11
cliffyk
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I forgot to say that the a failing but not necessarily dead, generator can cause EMI and RFI that have been known to mess with the crank and cam position sensor signals. As the generator brushes near the end of their life they no longer make as firm contact with the slip rings as they should.

I have not heard of this manifesting itself as a heat-related issue, though even at my age I have not yet heard of everything...
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Old 01-29-2013, 01:26 PM   #12
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I will check those fuses. If you think of any other suggestions could you please let me know, I would appreciate it.
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Old 01-29-2013, 01:28 PM   #13
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When you say generator do you mean the alternator?
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Old 01-29-2013, 01:39 PM   #14
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Quote:
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I forgot to say that the a failing but not necessarily dead, generator can cause EMI and RFI that have been known to mess with the crank and cam position sensor signals. As the generator brushes near the end of their life they no longer make as firm contact with the slip rings as they should.

I have not heard of this manifesting itself as a heat-related issue, though even at my age I have not yet heard of everything...
Friction causes heat and heat causes expansion. If there is wear in the alternator and the internals heat up and get sloppy this may cause the problem (me just thinking). This could also be the source of the bearing/belt squeal I was hearing. Again just me thinking out loud
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Old 01-29-2013, 06:18 PM   #15
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I started it up tonight and I noticed that all the guages were pointed to the left. Immediatley after the engine fired all the guages point to the right and then back to the left. I don't ever remembering this happening before the stalling issue occured. Does this mean somthing?
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Old 01-29-2013, 06:48 PM   #16
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It most likely means fuse #21 (5A) in the central junction box is blown, or there is a wiring problem. That fuse supplies constant power to the cluster to maintain data in its volatile RAM, if that power is cut the cluster does a reset/calibration when key is turned on.

Another possibility is that the battery is bad. Have you checked the battery voltage before (12.6 V for a fully charged battery), during (should not drop below 10.5 V), and after cranking the engine over (should come back up to 12.0 V or better)?
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Old 01-30-2013, 08:08 AM   #17
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I spoke online with a Ford tech last night and he seems to think the stalling issue is related to the cam sensor, crank sensor, or computer. But I don't understand why it stalls only when the car is at operating temperature. Any thoughts? If it is one of these issues would they be difficult to fix on my own? I understand cars but am by no means a qualified mechanic.

He also said the gauge issue is is related to a low charge of the battery or the alternator starting to die. When the key is turned it is resetting the computer and clearing the codes and check engine light.

On the 4.6 L what is the likelyhood that the cam/crank sensor or computer went bad? Or could this be the EMI/RFI issue you mentioned above?

Again, thanks for you attention to this, I appreciate it.
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Old 01-30-2013, 08:58 AM   #18
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I'd get a cheap spark plug tester myself, and see if all are/will fire when this occurs. Perhaps borrowing or buying a cheaper code reader to view any that occur when it dies. Tapping on those sensors with the butt-end of a screwdriver (with car running and cold) if they're going will usually let you re-create the issue as well.

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Old 01-30-2013, 09:42 AM   #19
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Quote:
Originally Posted by Tyr View Post
I spoke online with a Ford tech last night and he seems to think the stalling issue is related to the cam sensor, crank sensor, or computer. But I don't understand why it stalls only when the car is at operating temperature. Any thoughts? If it is one of these issues would they be difficult to fix on my own? I understand cars but am by no means a qualified mechanic.
It is not uncommon for the crank and cam sensors to fail, keep in mind they are 12-years old, their operation could be affected by heat. They are not that difficult to change.

Here is the procedure for the cam (CMP) sensor;

and for the crank (CKP) sensor.

here is how to test the CMP;

and the CKP.

Quote:

He also said the gauge issue is is related to a low charge of the battery or the alternator starting to die. When the key is turned it is resetting the computer and clearing the codes and check engine light.
He is correct, as I said above if the voltage while cranking the engine drops below 10.0 V the instrument cluster and PCM will reset--both battery and generator performance could also be affected by heat.

Quote:

On the 4.6 L what is the likelyhood that the cam/crank sensor or computer went bad? Or could this be the EMI/RFI issue you mentioned above?

Again, thanks for you attention to this, I appreciate it.
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Old 01-30-2013, 10:09 AM   #20
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When you say generator do you mean the alternator?
No, I mean the generator--our cars do not have alternators, nor do most modern vehicles:



An alternator is a device that converts mechanical energy to alternating current electrical energy. Generators are similar devices that produce direct current output. Real engineers know this and as real engineers tend to be explicit in their communications and documentation they would not call that which is in our cars an alternator.

Way back when the rectifiers were mounted externally to the mechanical device driven by the engine, that device was sort of nick-named "alternator" to differentiate it from the older commutator . When the rectifiers became internal to the device it became a generator--but in the mind of the general public, and other ill-informed communities the name "alternator" stuck.

But calling it one does not make it one--oddly we call the things used at work sites and after hurricanes "generators", which they are not as most create only alternating current output. Go figure.

If you want to have fun print out the excerpt from the shop manual and bring if you have to go to an auto parts store. Pull it out after they demean and chastise you for asking for a "generator"...
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