My 2001 Dodge Neon idles rough in drive and reverse but idles fine in park and neutral. I have changed the spark plugs, air filter, spark plug wires, and the coil pack. I just recently had my transmission serviced (flushed and refilled), my throttle body cleaned, my oil changed, my fuel filter and pump replaced, PCV valve replaced, and my fuel injectors cleaned. I have check for error codes but none were found. I did a cylinder pressure test on each cylinder to check for a cracked head or gasket, all pressures where in the normal range and the same for all four cylinders. There are no signs or sounds of a vacuum hose leak. I have noticed that it only idles rough when the engine is at normal temp (warm). When I first start it and drive a minute or two and stop, it idles normal. I have checked the timing and it seems to be correct. I have also tested the throttle position sensor and it also seems to be working correctly. I have put A LOT of money into solving this problem but none of the above worked. What else could be causing it to idle rough only in drive and reverse? Oh yeah my idling RPMs are around 600. Way to low!My 2001 Dodge Neon idles rough. How can I fix it (2)?
a can of throttle body cleaner sprayed while someone holds your gas pedal down while running.My 2001 Dodge Neon idles rough. How can I fix it (2)?
Did any of the old spark plugs look different then the other 3. If one looked oily it could be missing on that cylinder. If one looked white it could be leaking anti freeze into that cylinder. I have seen new spark plugs be bad. Try pulling one spark plug wire off one at a time to see if it makes the engine run worse. If one of them doesn't make it get any worse, that is the cylinder that it is missing on. Please I hope you are using champion spark plugs.
