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Discussion Starter · #1 ·
This just happened earlier today for the first time. The engine was not fully warmed up, and the outside temperature was cooler than usual (for north TX) in low 50's, maybe even 50° on the dot? When I braked and came to a stop fairly gently (not grandma-style easy, but normal easy), no issue. But a hard stop (no tire chirping) resulted in the engine dying, twice. Restarted no problem. The only other issue I can recall is twice now, while gear in Drive, there was a hesitation in movement...meaning it wouldn't move forward on its own like you'd expect an automatic trans to do, I had to press the gas pedal for it to move and when I did that, there was a bit of a lurch. Otherwise, it shifts beautifully. When warmed up, there appears to be no issue. I have no check engine light, or any other light on the dash, so I didn't hook up my scanner.

Based on reading from some other posts, I'm suspecting the trans solenoid, but would like to get some input to either confirm this or engage some further questioning that I may not have considered. Trans did have filters and fluid changed (correct fluid type, per owners manual) not long ago, but again, it seems the colder weather is the only variable that has changed.
 

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Discussion Starter · #2 ·
Follow up: it also occurs to me that it could be a vacuum leak, perhaps a bad power brake booster or connection. Also, I stated I suspected the trans solenoid (implying trans solenoid pack) but I believe TCC solenoid would be more accurate to suspect.

Here's a question: as a way to test this, could I shift the gear into Neutral, while at speed) and then brake hard and come to a stop to see if it still dies, and if it does, would that rule out the TCC solenoid and more definitively point to a brake vacuum leak?
 

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Follow up: it also occurs to me that it could be a vacuum leak, perhaps a bad power brake booster or connection. Also, I stated I suspected the trans solenoid (implying trans solenoid pack) but I believe TCC solenoid would be more accurate to suspect.

Here's a question: as a way to test this, could I shift the gear into Neutral, while at speed) and then brake hard and come to a stop to see if it still dies, and if it does, would that rule out the TCC solenoid and more definitively point to a brake vacuum leak?
Will you run out of brakes if the engine dies while you brake at speed in neutral JW?
 

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A friend of mine had a similar issue after few time after transmission oil change: the mechanic used poor quality filters and one of the two ones felt down in the trans oil pan after few time.
No issues in normal shifting, only engine dying sometimes at stops.

It is only an idea, a possible check.
 

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Discussion Starter · #5 ·
Will you run out of brakes if the engine dies while you brake at speed in neutral JW?
I was able to do this test a bit ago, needed to run to the store and had the opportunity with no one behind me. I put it into Neutral and braked a bit harder, trying to emulate what occurred before, but the engine didn't die this time. Only other symptom I noticed (again, this one is new) is while I was stopped readying for a U-turn, it felt like it was surging, like trying to fight the brakes and the RPM's dipped down and it ran a little rough at that idle speed.

So I think I can probably eliminate brake vacuum leak and I'm now leaning towards transmission solenoid issues, or potentially a low trans fluid level (it's been driving fine, but since topping it off after all the work I've put into it, it's possible I suppose that the fluid has finally worked its way through the trans and is now a bit low. Kinda doubt it, but it's a possibility. Any further thoughts given this information?
 

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Yes. Swap the TPS (throttle position sensor). Super easy to do and a common fail part. When it does fail, it will eventually throw a code but prior to that you can have the things described occur.
Other items that could be causing this is a failing alternator. For whatever reason, Jeep WJ engineers decided that the alternator will barely have enough output to keep the WJ running and actually relies on the battery to supplement power draw even while running, then feeds the battery voltage again once RPMs are up. While coming to a stop and as RPMs drop, the battery that has some age on it is not able to keep up with the sudden demand well enough and the aging alt is struggling to put out enough voltage to keep the engine running at low RPM, especially when there is a sudden RPM drop like when coming to a stop.

Since the TPS is an item that's cheap to swap and fails about every 6-7 years, you're fine to use a parts store unit with a lifetime warranty rather than the OEM unit. The OEM unit fails too.
It has 2 torx bolts to remove.
Also clean up the battery terminal contacts to ensure you're getting all of the amperage needed at all times.
If the issue still occurs, grab an alternator specified for the '01 Durango for a higher amp output. It normally costs less too and is a direct fit.

If trans fluid is not leaking out somewhere, you're probably fine there. (Stop adding supplements to the fluid, it's no bueno on the WJ and won't fix anything.) Also, the symptoms described do not match with a trans issue.

So clean the battery contacts and swap in a new TPS. Then pony up for the new alt if needed.
 

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Discussion Starter · #7 ·
Double E, thank you so much.

As it turns out, I ordered a new TPS and an IAC after I did some more googling of the symptoms and thinking about what the issue could be. So I'll getting those tomorrow it looks like and I'll do that swap.

As for alternator, I actually did put in a new 160 amp one meant for durangos, so I would be very surprised if it had an issue. I did do a voltmeter test on it while idling right after I installed it a few months back and I believe it was at 13.65? Somewhere in that neighborhood. The battery (which is 2 years old, but had been sitting unused for most of that time) had just been charged up out of the vehicle, so maybe it wasn't charging at a higher voltage because the battery was already "full"? Not sure. But anyway, if I still have this issue after replacing those 2 sensors (went with Standard Motor Products on both) I'll have the alternator tested.
 

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If you're going to swap the IAC, you'll get maximum benefit from also pulling the TB and cleaning the back side of it and the cavity where the IAC goes.
2 bolts to remove the airbox (one underneath the airbox on each side, 10mm)

Then (I think) 3 8mm bolts to loosen the TB. Before removing it, carefully pull the cruise control and throttle cables from their plastic mounts, disconnect the IAC & TPS and one vacuum hose from the back. If the TPS has never been removed, those torx bolts will be in there with a lot of force, so be sure you use the right torx bit to avoid stripping it.
 
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Yes. Swap the TPS (throttle position sensor). Super easy to do and a common fail part. When it does fail, it will eventually throw a code but prior to that you can have the things described occur.
Other items that could be causing this is a failing alternator. For whatever reason, To get more MPGs Jeep WJ engineers decided that the alternator will barely have enough output to keep the WJ running and actually relies on the battery to supplement power draw even while running, then feeds the battery voltage again once RPMs are up. While coming to a stop and as RPMs drop, the battery that has some age on it is not able to keep up with the sudden demand well enough and the aging alt is struggling to put out enough voltage to keep the engine running at low RPM, especially when there is a sudden RPM drop like when coming to a stop.

Since the TPS is an item that's cheap to swap and fails about every 6-7 years, you're fine to use a parts store unit with a lifetime warranty rather than the OEM unit. The OEM unit fails too.
It has 2 torx bolts to remove.
Also clean up the battery terminal contacts to ensure you're getting all of the amperage needed at all times.
If the issue still occurs, grab an alternator specified for the '01 Durango for a higher amp output. It normally costs less too and is a direct fit.

If trans fluid is not leaking out somewhere, you're probably fine there. (Stop adding supplements to the fluid, it's no bueno on the WJ and won't fix anything.) Also, the symptoms described do not match with a trans issue.

So clean the battery contacts and swap in a new TPS. Then pony up for the new alt if needed.
My alternator produces enough current to run all the electrical toys bar the cigar lighter an HO has at tickover.
Which is just as well since it's output voltage only charges the battery slowly.
Output voltage is normally 14 or less.
 
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