1997 Dodge Neon 4 cyl Front Wheel Drive Automatic 140k miles
One cold morning, starts up fine, idles while putting kids in, buckling up and about to shift into reverse, and engine bogs and dies, can't get it to start, turns over but no indication of combustion.
(DOHC) No engine codes or check engine light. Timing belt tight & intact, take each plug wire and can spark another plug (grounding on the valve cover), electrically checked each injector, pulled fuel rail out and then visually verified each injector pulsing little clouds of gas. These tell me that ignition module/coils are working, injectors are working, and PCM is operating them in some semblance of order.
We also pulled each plug and cleaned them up, had some spares should have tried them, but they appeared fine.
Also tried a test found on AutoZone, using a test light to see when the ASD is energized, when PCM is providing 12V to ignition coil, and the flashes indicate whether PCM is receiving signals from cam/crank sensors. Since 96-99, test says disconnect crank sensor, and test (results in flashing during cranking) indicates crank sensor is bad, but we bought a new one and the same test comes up with the same result, as well as the no start.
My buddy thinks something could be wrong with the #1 cylinder/plug/port off the ignition module, we found some scorching on that post on the module, and a little blow-back (oil) on the #1 plug, but my thinking is that something centralized is wrong (bad PCM, or bad timing/signals), because I would think I would hear 3 of the 4 cylinders trying to fire, and all 4 cylinders didn't all break at the same time.
We tried a compression test, but the recessed plug holes weren't working with the rubber hose, we got it as tight as we could, but simply pulling up on the hose during test yielded much higher pressure, so we were sure we weren't tight.
I guess I'm trying to get better ideas of procedures and tests to narrow down the possible bad components. We've replaced ignition module, plug wires, and crank sensor, with absolutely no difference. Getting into where the parts that it could be are getting expensive, like the PCM or possibly an engine rebuild, and I'd really like to have some certainty that I'm heading in the right direction or that it's even worth repairing instead of replacing it.
have the same problem?
Wednesday, January 27th, 2010 AT 11:58 AM