Hi, My 2002 2.7 Litre Sebring has a bad misfire. Codes po300 and po303. changed all plugs and coil pack on number 3 cylinder.mechanic also checked injectors, says they are fine. No oil dripping anywhere in engine or ground, clean oil. Lost from here, any help is appreciated.

 

power and ground to coil power and ground to injector compression test?

 

CT, Thank-you. My mechanic has replaced all plugs, #3 coil and has okayed fuel system. Also went to dealer today and had pcm reflashed, No change. Although for a very short 5 minute trip today it ran perfect??Its back to flashing MIL and missing badly now.
Thank-you

 

Still no luck here.... Added 1 quart of Lucas upper cylinder cleaner and sprayed out and scrubbed throttle body with cleaner tooth brush and clean rag. Will try again later to see if this helped.

 

it wont help still need that basic info I mentioned in teh post above

 

Ct, yes 'mechanic said both these procedures were done and both ruled out. One code today on reader.... P0303. Still has a serious misfire'

 

ij here is how things go if you have working spark plug coil and injector then only thing remain is internal engine aka valve or pinion area or warped heads due to over heating.

 

Ct, thanks for your input. Local mechanic did a compression test and hooked up diagnostic equipment. No compression in cylinder #3. Says stuck or bent valve, as this car did not over heat. Would you agree with the mechanic that this is not worth pursuing? Also, are there any additives or other quick fixes that are worth a try that may free up this valve. Thanks again, much appreciated.

 

Why is it, any ideas would be appreciated, that when I start the car its rough as hell with it running on 5 cylinders, Ill red line it 2 or 3 times in low gear and the car will run PERFECT until its shut off and started again. Over to you you Mr,CT.

 

CT. You Mute?