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Old 04-18-2012, 04:34 PM   #1
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4.0 randomly dying at stops.

as the title says, my engine has been hard starting and dying when cold. also sometimes when at a complete stop. i seafoamed it a week ago. is it possible that caused the issue? just replaced spark plugs because i thought they had been fouled by the seafoam. cleaned throttle body and MAF sensor. thoughts?

maybe bad compression in a cylinder? i just dont know why it would surface now...

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Old 04-18-2012, 05:15 PM   #2
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May be the crank sensor try to get it to autozone and have them pull the codes

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Old 04-18-2012, 05:51 PM   #3
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Is the CEL on? If so pull the codes and post them up here.
If not, it could be a number of things. ( clogged/dirty filters, bad fuel)
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Old 04-18-2012, 09:12 PM   #4
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its not throwing any codes
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Old 04-18-2012, 09:40 PM   #5
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Change the distributor cap and rotor. Moisture is makin you chug and stall out. Sounds like misfire.
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Old 04-18-2012, 10:02 PM   #6
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mines an 01. no distributor.
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Old 04-18-2012, 10:34 PM   #7
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i got the alternator and battery tested when it first started acting up. alternator was good, battery needs to be replaced apparently. i did do some heavy winching a week or so before this all started up...
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Old 04-19-2012, 12:52 PM   #8
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I've been fighting similar issues and since you didn't specifically mention it be sure to check your IAC.
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Old 04-20-2012, 08:20 AM   #9
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my mistake: i cleaned the throttle body and sprayed cleaner into the IAC. i guess ill take the IAC apart and give it a good cleaning now.
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Old 04-20-2012, 09:43 AM   #10
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i guess ill take the IAC apart and give it a good cleaning now.
Removing the IAC and giving its plunger and the oriface in the throttle body it fits into a good cleaning is your next best step. Use some aerosol throttle body cleaner and an old toothbrush on the IAC. For the oriface in the throttle body, use a baby bottle nipple brush.

Don't push/pull/spin the IAC's plunger.
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Old 04-21-2012, 10:12 AM   #11
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gave the IAC a good cleaning. still stalling out
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Old 04-21-2012, 10:18 AM   #12
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Does the engine rev up from idle smoothly if you apply the gas slowly and smoothly? I'm beginning to think TPS (throttle position sensor) now.
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Old 04-21-2012, 10:45 AM   #13
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Does the engine rev up from idle smoothly if you apply the gas slowly and smoothly? I'm beginning to think TPS (throttle position sensor) now.
yep. no issues there.
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Old 06-05-2012, 10:28 PM   #14
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Your plugs aren't gapped properly.

I know most will argue with me on this one but I am learning the hard way
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Old 06-06-2012, 05:13 AM   #15
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Your plugs aren't gapped properly.

I know most will argue with me on this one but I am learning the hard way
Probably would've been my guess after having cleaned the throttle body.

NEVER ever trust the gap on plugs out of the box!
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Old 06-08-2012, 06:43 PM   #16
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same thing happened to me. what s nightmare.

replaced tthe O2 sensor, still stalled.

replaced the throttle body sensor. still stalled.

ended up being the fuel pump and throttle body sensor combination.
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Old 06-09-2012, 05:07 PM   #17
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May be the crank sensor try to get it to autozone and have them pull the codes
I am also starting to believe that the Crankshaft Position Sensor serves a much greater role in the proper operation of a Jeep than most people give it credit for.
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Old 06-09-2012, 05:13 PM   #18
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I am also starting to believe that the Crankshaft Position Sensor serves a much greater role in the proper operation of a Jeep than most people give it credit for.
The crankshaft position sensor provides the engine's master timing signal. Without it, the engine won't run. I'd say it has a pretty important role.

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