Expert: Roland Finston - 6/30/2011

Question
Dear sir,

I have been experiencing problems with my car. it is a chrysler sebring 2003, 2.4 liter, DOHC. The car failed to start sometimes, the autozone computer indicated that the camshaft sensor was having issues. I replaced it and the car stopped having the starting failures but it then turned to the engine missing when acceleration is in progress, even when it's parked. I have replaced the TPS sensor, spark plugs, spark plug cables, coil harness and it didn't fix it. I even replaced the OEM computer as an electrician told me it was the reason for the engine missing after having replacing so many parts already. That didn't fix either. The electrician then told me that the new OEM computer had been programmed to cut the fuel injectors at 2500 RPMs and not at 5000 RPM as a engine protective measure. Indeed the engine starts missing when it reaches RPMs between 2000 and 2500 but I don't believe it's the OEM computer since the issue started when the car was working with the original OEM computer.

Lastly, I put back the old camshaft sensor and the engine did not miss anymore but I am afraid It's going to fail to start eventually.  I got another new sensor but the engine misses again.  The computer codes have been celared but it points to the sensor again.  Im at a loss and don't know what to do anymore.

Answer
Hi Jose,
Once a rotational sensor starts to fail, it is likely to remain flakey as you have observed, so I would put back a new/newer sensor that has not caused a code so far.
On the missing, the only thing I can suggest is that you keep doing the self test using the ignition key approach until a new specific code appears that would give us clue. About the only areas that I can suggest that you inspect would be the hoses that are attached to the intake manifold (vacuum lines) as any one of those that is loosely fit or cracked could monmentarily flex and admit air into the manifold which would provoke a miss. Also you could clean the throat of the throttle body and both sides of the throttle plate with solvent. A compression test might reveal an issue with one of the cylinders being out of spec. Ideally we will get a code.
Roland
PS Please 'rate' my answer, and where you see the question about a nomination of me to be 'volunteer of the month' consider a 'yes' response . Thank you.
Sorry for the delay in answering but I just found your question in the 'pool' to which it was referred by Kevin.