92 Plymouth Acclaim

Have you checked the oil to see if it has any coolant in it, or the coolant for oil? That will tell you if you have a head gasket failure. If that's OK, one easy and cheap thing you could do is a good quality injector cleaner in the gas. You can get that at any decent auto parts place. Make sure it is recommended for your type of car, fuel systems vary.

Beyond that, you need to get the codes read. This is not difficult but requires a shop manual and some technical knowledge, so you need to have it done at a competent shop. It may be only a sensor, but you need a diagnosis to know for sure.

Thanks for the advice,I did mention in my first post that the Oil was free of coolant and coolant free of Oil. I did run the car at a Idle with the Radiator Cap off it did not bubble up but it did come to the top of radiator into the overflow tank which seemed normal not sure with it not being under pressure. Will try the fuel injector cleaner and check the wires. Thank You Gentlemen for your reply.

Well, the first thing to do is to check the computer codes.

To check the computer codes:

With the engine off, switch the ignition key on-off-on-off-on, leaving it "ON". Do not go to "start", just "on" during this procedure.

Watch the "Check Engine" or "Power Loss" light. It will turn on, then go off, then will begin to flash-out any trouble codes that have been stored. For instance, if it flashes:

flash flash flash

flash flash flash flash flash flash flash flash

flash flash flash flash flash flash flash flash flash flash

Then you have a 12 (one flash followed by two) a 35 (three and five) and a

55 (five and five). 55 means "end of codes" or, if by itself, "No codes stored. Check the codes and report what you find.

The next thing to do is to tell us how long it's been since the timing belt was replaced.

DS

Not a timing belt problem, if the timing belt was off by one tooth it would throw the map sensor way off and cause low vacuum, what does low vacuum tell the computer DS?? it tells the computer that you are under a load and to give it more fuel, what does more fuel do at idle DS? it makes it run really bad. his complaint is under a load and idles good Secondary ignition

Well, whoever you are, you get an A in theory and an F in real world.

One tooth? Cause enough vacuum change AT IDLE to throw the MAP sensor that far off?

Nuh-uh. Several teeth, maybe. One tooth, not a chance.

Guys, not only will one tooth off screw up the MAP signal, having the belt tension too tight will do it also, especially in a cold climate. The MAP signal is sinusoidal, the SMEC/SBEC actually takes the amplitude of the signal into account. That is one reason ChryCo vehicles were/are so sensitive to MAP problems.

The cam timing might be the problem, and it might -not- be the problem, but since it takes less than 2 minutes to check and verify, it would be reasonable to do so as part of the diagnosis.