Mechanics

STUMPED ON MISFIRE

1996 Dodge Caravan

I have a 1996 Dodge Grand Caravan with the 3.8L engine. In January, the car started to shudder and engine misfired. The ODB II scan read P0305-Cylinder no. 5-Misfire Detected. I replaced all six spark plugs and wires with Bosch Platinum Plugs and Bosch wire set. The car ran fine for two months. The engine then started to misfire again. The OBD II codes read P0352-Ignition Coil no. 2 Primary Circuit and P0300-Random/Multiple Cylinder Misfire Detected. I replaced the ignition coil with a coil from Pepboys and inspected the wiring to the coil. The car still misfires in cylinder 5 and the code P0352 is generated from the computer. I took it to the mechanic. He inspected the plug in cylinder 5 and said it was ok, but it had a little oil on it. He replaced the plug and the car still misfires. He said I should use a coil from the dealer. The dealer told me for the 1996 it did not matter. I tested cylinder 2 and 5 with new wires since they are on the same coil bank. I replaced the O2 sensors in November '06. All vacuum tubes are intact and the fuel injectors and their wiring are fine. The battery and alternator seem fine and I have had no issues with the system grounds. Should I use the dealer coil? Could my problem be the camshaft or crankshaft sensors? Could the problem be electrical? Do you have any suggestions on what I should do?
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Gpcaravan
April 24, 2007.



Could be bad gas, vacuum leak, bad coil, dirty injectors and EGR.

If the EGR valve fails to close when EGR is not required, or if it leaks because of carbon buildup on the valve stem or valve seat, exhaust will be sucked into the intake manifold all the time creating a lean fuel mixture. This will cause lean misfire and set a random misfire code

Rasmataz
Apr 25, 2007.
There might be oil seepage around spark plug tubes, if you pull spark plug wire boots off spark plugs and look down in tube with a bright light, if there is oil down in bottom around spark plug base or on the wire end that you just pulled are oiled, you need to replace valve cover gaskets and tube rings, if you replace yourself, buy chilton book for proper sealant info

Tiny
Steelworker
Apr 28, 2007.
The EGR seems to check out. I put in a gasket sealing fluid to test if a gasket is leaking oil into the spark plug well. It is still misfiring. I have noticed the following the only error I am getting is the P0352 and the MIL is blinking. However, when the car runs down to empty on gas the MIL stops blinking and it runs that way for a few miles after filling up - still misfires. Then it is back to blinking. Do I need to use the dealer ignition coil instead of a generic from Pepboys. Might there be something wrong the fuel pump? How would I check?

Tiny
Gpcaravan
May 21, 2007.
Try checking the fuel pressure-low pressure equals to lean mix.

Rasmataz
May 21, 2007.