At A Stump HELP -

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post #1 of 4 Old 02-03-2014, 08:51 PM Thread Starter
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1987 MJ Comanche 
Join Date: Feb 2014
Location: castle rock
Posts: 4
my 4.0 will not run right HELP!!!

I just bought a 1987 jeep Comanche 2WD 4.0 with 5speed
I am at a loss since when I test drove it she ran like a gusty 4.0 should loads of torque, now it is acting up
it was stalling and dying and the tachometer was jumping all over the place
so I did this so far
cap, rotor, wires, bosch platinum plugs, CPS, IAC, Fuel filter, all vacuum lines inspected and replaced as needed, Coil ,Ignition control module,
after all this a few hundred dollar's later she idles and revs only to around 2800rpm then dies out and falls on her face
also running very rich
I cant figure this out new TPS is on order
any other suggestion's , I am about to Craig's list her and walk away

Last edited by bozzman080; 02-04-2014 at 12:02 PM.
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post #2 of 4 Old 02-04-2014, 05:48 PM
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1987 XJ Cherokee 
Join Date: Jul 2010
Location: Central
Posts: 631
unplug the Crank Position sensor and plug it back in and get one to replace it.
I would also suggest pulling it out and cleaning it off and might even try drilling
one of the holes out to a 3/8" so you can get it a little closer for better signal.

My 87 Renix occasionally won't start, when it happens, I just unplug mine and
plug it back in and its good for 2 to 4 months.

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post #3 of 4 Old 02-04-2014, 06:57 PM
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1990 MJ Comanche 
Join Date: Oct 2009
Location: Prescott
Posts: 11,194
Click on the link in my signature. Do posts 1 through 5. Platinum plugs suck BTW. NGK all the way.

If you own a Renix Jeep, you'll want to check this out.

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post #4 of 4 Old 02-04-2014, 10:58 PM Thread Starter
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1987 MJ Comanche 
Join Date: Feb 2014
Location: castle rock
Posts: 4
Shes alive , i can not believe it was the cat it was beyond plugged up so if you have done all that i did check that
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hesitating , no power

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