I have read through a number of threads regarding misfires and P030x codes and haven't seen or come up with a solution that will help resolve our issues and am seeking advice on next steps.
We don't have a long history with the car, some some things are unknown. What we do know is:
Car has difficulty starting - usually cranks 10-20 seconds before it catches and usually needs a little gas to get it to catch. This will result in a plume of blue-gray smoke and a rather prominent gas smell.
Once running you can see and feel engine vibration. Not horrific, but also not the way Jeep designed it to run. It was also giving misfire codes.
The car was taken to a shop and they recommended replacing plugs. we replaced all 6 as well as the ignition coils, as they were very old and had minimal life on them. None of the plugs were not gassy, oily, or otherwise fouled - just worn. The car continues to have difficulty starting and continued to give misfire codes of 301, 303 & 305. Compression gauge were put on cyl 1, 3 & 5 (drivers side bank) and all 3 had good compression above 120-130. We also sprayed around the engine and manifold looking for vacuum leaks and none were present. We ran a can of seafoam through the tank and have just added a can of 44K.
Since the Seafoam, Its still hard to start, however, if the car is cold, it will run with no CEL locally, highway etc...Once hot and re-start it will throw a misfire code - sometimes only 301 & 305, sometimes 301, 303 & 305. It runs fine at rpm, but as soon as i come to a stop light and sit, the CEL will start blinking and the shudder is a lot more prevalent.
There are no other error codes I'm getting, so I have been hesitant to start replacing IAC, O2 sensors etc... but am running out of options. I also have not disassembled the fuel rail or started to replace or move around injectors. I find it hard to believe that 3 injectors are bad, and hoping the 44K will clean / clear out any gunk in the rail or injectors.
Car runs great at 2500rpm and 70mph. but as soon as I come to a light - its not a happy camper.
Thanks in advance for suggestions or comments.
dean
We don't have a long history with the car, some some things are unknown. What we do know is:
Car has difficulty starting - usually cranks 10-20 seconds before it catches and usually needs a little gas to get it to catch. This will result in a plume of blue-gray smoke and a rather prominent gas smell.
Once running you can see and feel engine vibration. Not horrific, but also not the way Jeep designed it to run. It was also giving misfire codes.
The car was taken to a shop and they recommended replacing plugs. we replaced all 6 as well as the ignition coils, as they were very old and had minimal life on them. None of the plugs were not gassy, oily, or otherwise fouled - just worn. The car continues to have difficulty starting and continued to give misfire codes of 301, 303 & 305. Compression gauge were put on cyl 1, 3 & 5 (drivers side bank) and all 3 had good compression above 120-130. We also sprayed around the engine and manifold looking for vacuum leaks and none were present. We ran a can of seafoam through the tank and have just added a can of 44K.
Since the Seafoam, Its still hard to start, however, if the car is cold, it will run with no CEL locally, highway etc...Once hot and re-start it will throw a misfire code - sometimes only 301 & 305, sometimes 301, 303 & 305. It runs fine at rpm, but as soon as i come to a stop light and sit, the CEL will start blinking and the shudder is a lot more prevalent.
There are no other error codes I'm getting, so I have been hesitant to start replacing IAC, O2 sensors etc... but am running out of options. I also have not disassembled the fuel rail or started to replace or move around injectors. I find it hard to believe that 3 injectors are bad, and hoping the 44K will clean / clear out any gunk in the rail or injectors.
Car runs great at 2500rpm and 70mph. but as soon as I come to a light - its not a happy camper.
Thanks in advance for suggestions or comments.
dean
