I have a 1999 honda civic ex 2 door coupe. I changed the idle control valve, spark plugs, fuel pump, some vacuum lines, the pcv valve and hose, checked all lines for leaks, replaced the 02 sensor twice, readjusted the throttle position sensor (its in proper range with no glitches) new spark plug wires, cap and rotor, new injectors as well! And I STILL get a warm start, RANDOM, idle fluctuation, like the car cant determine the air fuel ratio for a minute, so the idle surges up/down until it finally settles. Also when this happens the car has a slight power loss when driving and the muffler gets louder. I put on a new header, catalytic converter, and stock exhaust on the car and STILL the problem exists. I have also cleaned the throttle body, the engine with seafoam a few times, I have adjusted the idle as my manual says and replaced the throttle body gasket with an oem honda one twice. I have bled the coolant system several times, in case air is causing the idle surge to no avail. The engine compression checks out fine as well. I have done all oil changes and transmission changes.
Im now thinking coolant temperature senor?(Although it seems to detect the temp just fine) or the pcm itself? Or my map sensor. Could the map sensor cause this intermittent idle surge? ('Ive cleaned it twice) sometimes it doesnt happen at all and the car will run and idle flawless. Never does this on a cold start though. I've dumped alot of money in so far. Any hope?
have the same problem?
Tuesday, October 12th, 2010 AT 5:20 PM