Replaced Everything - STILL MISFIRING! Please Read This!
03-01-2011, 06:46 PM
#16
Just That Awesome
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Location: Hannibal, MO
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Year: 1993
Model: Grand Cherokee
Engine: 4.0
I'm not going to read this whole thing, but you didn;t say if you replaced the cap, rotor, or pickup coil (in the dist)
03-02-2011, 08:46 AM
#17
Go to a different dealer then register a complaint with Chrysler to make sure it's on file.
I bet if it wasn't under warranty they would find the problem and charge you up the ****!
I bet if it wasn't under warranty they would find the problem and charge you up the ****!
03-04-2011, 07:40 AM
#18
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Year: 1984
Model: Cherokee
Engine: 383" Chevy
A quick compression test will give you the information you need, should have been done before any tune-up stuff as you won't ever be able to get it to run properly if the compression is down in one cylinder which would indicate a burnt valve or broken ring,etc,.etc., Chevokeeman.
03-11-2011, 08:55 AM
#19
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Model: Cherokee
I found the problem on my 2003 Laredo. The wire harness was shorting out near the back of the head. There is a huge/tall head bolt sticking up on the drivers side, just under the harness at the back of the engine. Apparently it eventually rubbed all the way through and it was shorting out the wire to cylinder #1 causing the injector to stay wide open thus dumping fuel into the cylinder. I repaired the wire and put a vacuum sleeve on top of the bolt and loaded up the harness with electrical tape. I also used a zip tie to hang the harness.
Hopefully this helps someone else with a similar problem.
For the record, my symptoms were a flashing check engine light (indicating a misfire). The smell of raw fuel and of course rough idling, hesitation under load, etc.
Hopefully this helps someone else with a similar problem.
For the record, my symptoms were a flashing check engine light (indicating a misfire). The smell of raw fuel and of course rough idling, hesitation under load, etc.
09-08-2014, 02:50 PM
#20
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Model: Cherokee
P0303 - #3 Cylinder Misfire
I have an 03 Grand Cherokee, 4.0L Engine. 98,000 kms (60,000 miles) One really cold night (-30 degrees celcius) I started it up and it was misfiring. It had always been plugged in and regular maintenance done.
Ran the code, it was P0303 - #3 Cylinder Misfire. I read every stinkin forum post I possibly could find on every jeep website, and started doing all the recommended ideas. I read all the TSB's on this issue too. Including a trip to the Dealer and tried all of their ideas.
They said the injector was faulty and to replace it. Also change the plugs to the original Champion plugs, because I had bosch platinums in it. I did and after this and everything else i've tried, They're completely stumped. They have had it in on two separate full days and are now calling their tech support because they have no idea how to fix it.
Here's whats been done:
New spark plugs (twice, with the bosch in you can actually drive it. With the champions it chugs so hard you have to pull over)
New Fuel Filter
New fuel injector on cyl. 3
New Oil/filter change
Sleeves on all six injectors
Thermostat recently changed
Rear main seal done 1 year ago
Coil Pack Rail looks good, boots and coils inside them look new
Fuel pump tested and checks out fine
Battery tested and checks out fine
Combustion cleaner through throttle body
Even tried the Seafoam treatment
So It seems like the third plug is getting lots of fuel. The electrode looks green like fuel and smells of gas. The other plugs are black and 5 & 6 are a bit oily. My senior ford tech friend says that with all of that done to it and judging by all the carbon coming out of the exhaust and and the putt-putt exhaust, that it is likely a burnt valve/ring. I have read the TSB's about the valve rotation and I am starting to believe that it needs a valve job.
The only thing is that it should be covered under the powertrain warranty and the Dealer won't fix it because they still don't think that is the problem. Warranty is almost up, and they refuse to open it and check the valves. They are supposed to talk to their tech support this week, and the jeep will go back in next wed. I even made the service advisor read the TSB's.
I'll pull the head off myself if I knew that was the problem. What do you guys figure? Has anyone resolved their misfire? So many of these with the same problem. I think it's time Chrysler made it a recall. Class action suit is needed!
thoughts?
Ran the code, it was P0303 - #3 Cylinder Misfire. I read every stinkin forum post I possibly could find on every jeep website, and started doing all the recommended ideas. I read all the TSB's on this issue too. Including a trip to the Dealer and tried all of their ideas.
They said the injector was faulty and to replace it. Also change the plugs to the original Champion plugs, because I had bosch platinums in it. I did and after this and everything else i've tried, They're completely stumped. They have had it in on two separate full days and are now calling their tech support because they have no idea how to fix it.
Here's whats been done:
New spark plugs (twice, with the bosch in you can actually drive it. With the champions it chugs so hard you have to pull over)
New Fuel Filter
New fuel injector on cyl. 3
New Oil/filter change
Sleeves on all six injectors
Thermostat recently changed
Rear main seal done 1 year ago
Coil Pack Rail looks good, boots and coils inside them look new
Fuel pump tested and checks out fine
Battery tested and checks out fine
Combustion cleaner through throttle body
Even tried the Seafoam treatment
So It seems like the third plug is getting lots of fuel. The electrode looks green like fuel and smells of gas. The other plugs are black and 5 & 6 are a bit oily. My senior ford tech friend says that with all of that done to it and judging by all the carbon coming out of the exhaust and and the putt-putt exhaust, that it is likely a burnt valve/ring. I have read the TSB's about the valve rotation and I am starting to believe that it needs a valve job.
The only thing is that it should be covered under the powertrain warranty and the Dealer won't fix it because they still don't think that is the problem. Warranty is almost up, and they refuse to open it and check the valves. They are supposed to talk to their tech support this week, and the jeep will go back in next wed. I even made the service advisor read the TSB's.
I'll pull the head off myself if I knew that was the problem. What do you guys figure? Has anyone resolved their misfire? So many of these with the same problem. I think it's time Chrysler made it a recall. Class action suit is needed!
thoughts?
I know this is an OLD post, but. In case anyone is having the same issue now, is your fuel injector.
If you bought an after market fuel injector, chances are it was deffective.
I bought 6 after market fuel injectors for my jeep and only 2 resulted in good condition. That means: FOUR (4) of the after marker fuel injetors were bad!
I would double check tour work if you are having this issue, but rotaring the trougle fuel injetor to a different fuel injector valve spot on the vehicle, to determine if it is that injector that is bad. WHICH I GUARANTY you it is.
If you replaced your fuel injectors recently and did not resolve this issue, need to get new injectos from the dealership. I know they are expensive as hell from MOPAR, but. They are made right.
Good luck on your quest to solve this issue with after market fuel injectors, they are garbage.
10-15-2018, 08:59 PM
#22
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Year: 1993
Model: Grand Cherokee(ZJ)
Engine: 4.0 I6
suck in the middle
This reminds me of my issues , I have a zj with wireing problems and runnin on 5 cyl. still tryin to figure it out have you tried map sensor?
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