Chrysler Repair: 96 Sebring no start


Question
QUESTION: I have 96 sebring jxi convertible with mitubusi 2.5 liter. have fuel and have spark. replaced distributor, crank sensor, map,tps,cts,plugs,wires, and replaced all fuses and relays. Engine will start and run if outside temp is below 10 degrees and will only run for about 20 minutes or so until engine warms up. after that it will not restart. I have checked all sensor plugins and a lot of wireing and I have come to the end of my rope.I have no codes. I`m beginning to think the PCM took a dive. Is there any way to check the PCM before I spend more money ? Can you help me with this problem ?

ANSWER: Hi Jimmy,
The part that doesn't have good self-diagnostic capability is the egr valve. It may well be that the valve stem is gunked up such that the valve is sticking slightly ajar which leans out the mixture too much to sustain an idle. So spray some WD-40 on the stem where it enters the valve body and then use the tip of a screwdriver inserted in the slot of the stem to move it back and forth to see if it is moving freely and that the internal spring-action is closing it to a dead stop.
Sorry for the delay in responding to your question but I just found it in the 'question pool' to which it had been referred by Kevin.
Please read the PS below and respond to it.
Thanks,
Roland

---------- FOLLOW-UP ----------

QUESTION: Roland first off, thanks for the response. Even though the EGR on my 96 Sebring may be open a little, wouldn't you say that the 2.5 liter would at least fire and attempt to start ? I noted to you that when cold outside ( below 10 deg ) the engine starts and runs excellent. After warmup it shuts down with no chance of restart. Also I found a NOTICE sticker under the hood stating that the PCM had been reprogramed on 5/dec/99. Am I still looking at the possibility of bad PCM ? This JXI convertible has been an excellent vehicle and don't want to junk it yet. I stated that I replaced tha crank sensor but just maybe the new sensor is BAD. Don't you agree ? Is ignition switch a possibility ? In my 35 years of turning wrench, rule of thumb is if you have gas and spark you have FIRE !!

Answer
Hi Jimmy,
The pcm if failed still will give a code for that so I would not opt for that route yet.
It sounds to me that the issue is fuel/air mixture related which is principally controlled by the cts, which you indicate you have replaced and checked its wires.
When you say 'no codes" is that via the ignition key routine and the check engine light for 2-digit codes, or via a code reader for 4-digit codes via the data link connector? Do you have corroboration that the code readout is happening (a code 55, or a 'done' message)?
The cts should read about 4,000 ohm when cold and drop down to around 1,000 ohms at operating temperature, so check that out.
It is possible that a sensor can be 'off value' but not so much as to set a code. That would be diagnosed with a diagnostic readout box that presents the readings of the sensors and then your noticing that one is inappropriate.
Did you lube the stem of the egr and verify that it is closing to a dead stop by the internal spring-action?
Let me know if any of these questions are helpful to you.
If you would be so kind as to do the 'Thank/Rate' button, and consider a 'yes' to the question about a nomination of me that would be most appreciated.
Roland