One of my wife's coworkers drives a 1997 Jeep Grand Cherokee Laredo. 4.0 6 cyl.
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Vehicle is stopping in middle of highway. Sometimes it backfires, sometimes it doesn't. Have changed all sensors, computer, fuel pump. Doewn't do it all the time.
O.K. you Jeep braniacs. What would you suggest to do next. The poor woman is going broke over this thing.
i know you said changed all sensors.. but are you sure you replaced the cam positioning sensor? ive seen that it has been a problem on the 4.0s and i know that when the sensor dies.. the engine dies.
I am not the one doing the work. I am just trying to help out with some good info.
Yeah, sheep, I wondered the same thing. Does ALL sensors really mean ALL?
I personally suspected the Crank position sensor if it has one. I also wonder about the coil. I know some of you guys know these vehicles like the back of your hand, so that is why I am putting it out here.
yea i had a 89 cherokee with the 4.0.... the oil seal in the distributor was bad and would get oil in there. it would kill the engine dead. sometimes it would run sometimes it wouldnt. i fought with it for about a week off and on.. finally pulled the distributor cap and saw the oil.. then i knew what was up. the camshaft/crankshaft position sensor will do that too. i have seen plenty of times on the big diesels the sensor goes bad or starts to go bad and it will miss or die alltogether... id MAKE SURE they replaced that one... just my opinion
must be what the electric chainsaw motor is for!
I will pass along what we have so far, and try to get more clues.
What year is the GC? That will make some differences in what steps need to be taken (example, 99+ 4.0 doesn't have a distributor or wires, it's a coil on wire setup).
WiLieR Wrote:What year is the GC? That will make some differences in what steps need to be taken (example, 99+ 4.0 doesn't have a distributor or wires, it's a coil on wire setup).
Sorry. I left off that tidbit. It is a '97. (Fixed the first post.)
sheepdawg Wrote:yea i had a 89 cherokee with the 4.0.... the oil seal in the distributor was bad and would get oil in there. it would kill the engine dead. sometimes it would run sometimes it wouldnt. i fought with it for about a week off and on.. finally pulled the distributor cap and saw the oil.. then i knew what was up. the camshaft/crankshaft position sensor will do that too. i have seen plenty of times on the big diesels the sensor goes bad or starts to go bad and it will miss or die alltogether... id MAKE SURE they replaced that one... just my opinion
yep this is where my money is at it gets overlooked all the time
twistedjeeper Wrote:yep this is where my money is at it gets overlooked all the time
With all the wet weather we have had lately, it could be moisture getting in the distributor if it is not sealed well between the cap and the distributor itself.
I have also had a distributor cap to carbon track on the inside, causing it to fire an incorrect cylinder.