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90 xj not starting and can't figure it out

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Old Apr 20, 2010 | 09:21 PM
  #1  
Doorless jeep boys's Avatar
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From: Palm city
Year: 89
Model: Cherokee
Engine: 4.0 AMC
Default 90 xj not starting and can't figure it out

Hey y'all I am new to the site and got a 90 xj 4.0 inl 6 it's the Amc motor I am trying to figure out what the possible causes are for it not starting I have all ready done the crank shaft postioning sensor in it and it still ain't starting I am getting good spark and fuel is the any possible way to read like a code off of it or anything thanks for all the help
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Old Apr 20, 2010 | 09:24 PM
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91familyxj's Avatar
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From: Las Vegas
Year: 1996 Limited
Model: Grand Cherokee
Engine: 5.2
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So you are getting good fuel pressure?
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Old Apr 20, 2010 | 09:25 PM
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if you are getting good spark and good fuel supply, then that only leaves one thing. compression. how did you check for spark and fuel?
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Old Apr 20, 2010 | 10:09 PM
  #4  
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From: Palm city
Year: 89
Model: Cherokee
Engine: 4.0 AMC
Default Starting

It just started it's running like it's outta of time it will start for like 2 sec then just die and runs really rough but it's not outta of time so it werid Any idea thanks
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Old Apr 20, 2010 | 10:35 PM
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Year: 1999
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got a timing light? also check the firing order maybe you've crossed plug wires.
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Old Apr 20, 2010 | 10:41 PM
  #6  
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From: Palm city
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Ok I will check that do you know where I can get the firing order at
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Old Apr 20, 2010 | 10:48 PM
  #7  
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From: Las Vegas
Year: 1996 Limited
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1-5-3-6-2-4 Just remember the timing is fixed.
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Old Apr 24, 2010 | 04:08 PM
  #8  
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From: Palm city
Year: 89
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The firing order was correct I am still lost
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Old Apr 24, 2010 | 05:14 PM
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From: Bristol,Pa
Year: 94
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Engine: 4.0L
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When was it last tuned? Fuel filter?

If it's been awhile i'd pull some plugs and check them, see if the contacts on cap and rotor arent corroded.

A clogged catalytic convertor can make it run rough like that, but usually starts. Any noises from it recently?
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Old Apr 24, 2010 | 06:44 PM
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From: Boomer, NC
Year: 1995
Model: Cherokee
Engine: 4.0L
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Crank sensor went out on my '95, would sit there and turn over but never start. even with a new one some times the spacing isnt correct between the sensor and flywheel, just a suggestion.

Last edited by bbbarker; Apr 24, 2010 at 06:47 PM.
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Old Apr 24, 2010 | 07:08 PM
  #11  
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From: Palm city
Year: 89
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I replaced that I think it's got be the distritbute pick up sensor
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Old Apr 24, 2010 | 07:12 PM
  #12  
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From: Palm city
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B
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Old Apr 24, 2010 | 08:19 PM
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I'd say maybe on the pick up. But you need to answer, how did you determine the fuel pressure? Really sure it's spark? Also you may want to get a noid light to make sure injectors are actually getting fire.
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Old Apr 24, 2010 | 08:39 PM
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From: so cal
Year: 1990
Model: Cherokee
Engine: 4.0
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Originally Posted by Doorless jeep boys
I replaced that I think it's got be the distritbute pick up sensor
The truck will still run with the stator unplugged.
Mine did the same thing and it was the coil.



Edit: I see you say it has spark, nevermind coil.

How do you know it has fuel? Have you checked with a gauge?

Last edited by cherokee77; Apr 24, 2010 at 08:47 PM.
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Old Apr 24, 2010 | 08:41 PM
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From: JERSEY ALL DAY
Year: 1989
Model: Cherokee
Engine: 4.0L
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check distributor indexing. Should point just past cyl 1 at TDC if i remember correctly.
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