A compression test would allow you to know if there are anything wrong with the valves and timing. Misfiring might not occur consistently and there are many possible causes.
Fuel delivery, valve and cam timing, vacuum leaks, camshaft and crankshaft position sensors are possibe causes.
The 3.9 L engine has the camshaft sensor in the distributor so it is not likely for it to be the cause as it would be all 6 cylinders that could be misfiring, so would the crankshaft position sensor.
Thursday, February 23rd, 2012 AT 11:47 AM