Random missfire at idle. P0300. No cylinder missfire code. No other code. Engine compression 120psi on all 4 cylinders. Spark plugs clean. Engine vacuum low but not swing wildly. No vacuum leaks. Small intake manifold easy to check vacuum leaks. Ignition timing dance between -5 to +15 at idle. When the engine rav to 1600 rpm every thing back to normal. Smooth no missing.I changed, swaped or disconnected every sensor and computer with no luck. Could the engine has mechanical problem but still have good compression? I also put gas treatment in the tank in case there has water. I filled tank 2 times after I burn up all the gas. Thanks
have the same problem?
Sunday, February 21st, 2016 AT 11:57 PM