1996 Plymouth Voyager SE

JOESU

MEMBER
1996 PLYMOUTH VOYAGER

My check engine light stays on constantly. The only time it goes out is if the gauges all go to zero. Then, I'm assuming the PCM has gone offline. However, this is not all bad as the van runs much better without the PCM. Why would this be true. It idles better, it will pull hills better, and it never hestiates when this occurs. However, after some period of time the gauges will come back on the van goes back to running rough and not pulling hills. When I have the PCM read it reveals that I have multiple misfiring on cylinders 1, 2, and 5. This has been the case for some time. I have had all the ignition components replaced at least twice and it will run smoother for a while and then it goes back to the way it was. I have had the PCM replaced but that didn't seem to have much of an affect on the performance of the van. Can someone please offer some advice on what the problem might be?

2 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Tell me my friend who is pulsing the injectors to keep it running w/o the PCM and where is the PCM getting its ignition reference signal.

If a misfire in a specific cylinder should lead you to check the spark plug, fuel injector and compression

Maybe try checking the CPS and a failing ASD relay-this one powers the coil and the fuel pump. Example: if a component requires a full battery voltage and its only getting 6volts it will not operate properly maybe you should check the voltages to the coil and pump and do some voltage drop tests.

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

I have had all the ignition components replaced at least twice-What are they?

Good Luck