04 grand cherokee laredo misfire

[mossyoaktj]

mom 04 laredo. has the v8 and now cylinders 1,3,5,7 are misfiring. when this started happening she said the oil pressure dropped and the fuel gauge dropped. any ideas as to what would have the entire side misfiring

[mossyoaktj]

just got this message about the jeep

it was running, then gauge dropped to 0 then died, rattled like sumpwas pluged up, drained oil, put new plugs in now wont start just back fires, i think the lifters might be collapsed and not pumping back up, and exhaust is closed, it blows carbon out the exhust bad

[flatlander757]

Have you inspected the wiring for the fuel injectors and the coil packs for the side with the misfires? Sounds like something happened to the wiring to cause only one whole side of the engine to run like crap. There's no way that every one of the lifters failed to pump up at once unless the whole head is just caked with sludge. They are VERY easy to pull the valve covers... I think the gaskets are even reusable.

It has a 4.7L right?

[Tool Man]

check the o2 wire is it touching the hedder? look real close i had this happen took a long time to find out what it was when it happened to me

My 2 Cents Good Luck

[mossyoaktj]

yes its the 4.7.

ill pass the info along i wont be home from japan for another 2 weeks.

thanks

keep em coming

[blazerbrad]

The "carbon" out of the exhaust is just black exhaust from running extremely rich from the one bank (cylinders 1, 3, 5, 7...these should be the driver's side bank). Really sounds like you have the fuel system working with the injectors putting gas in the cylinders but no ignition on that side. I looked through the wiring diagrams and I don't see a condition where broken wire would disable 1, 3, 5, 7 ignition coils only without affecting the other bank.

There is a chance the problem is not isolated to just the one side. The camshaft position sensor is kind of the nerve center of the fuel and ignition (acts like a distributor). I would check it (think it's on the passenger side front head). Always trace the wires for breaks and check the connectors first, then maybe try replacing it (they are only around $25.......and if it doesn't work take it back).

[mossyoaktj]

thanks we will keep trying. hopefully its something easy so it dont cost her a fortune.

[mossyoaktj]

ill be home sat nite so im goin to look over everything and probably replace the camshaft position sensor and hope that helps if not ill return it. anything i should check.