Subject:	engine hesitating and backfiring
Question:	(1998 eclipse rs 2.0 420a engine, stock) within the last 2-3 days my eclipse has started hesitating on accelerating. if you rev the engine from idle it will occasionally backfire. I have checked for diagnostic codes and get none. I used the "turn the ignition key on,of,on,of,on" within 5 seconds method. I have tried disconnecting the battery to reset the ecm with no positive results. back in the old days if my 69 camero with the 350 in it had had this problem it would have been an ignition advance/retard problem. any ideas? thanks for your time.
Answer:	Rich, You are correct to diagnose an ignition advance/retard problem. I've had this problem myself, and I know others that have experienced similar problems. In most of the cases, this is what cured the problem. Replacing the plugs, wires, dist rotor & cap, pcv valve, and O2 sensor. Try one at a time so you can pin-point exactly what caused the problem. If that doesn't help, replace the fuel filter and have your fuel pressure checked. If that fails, have your mass air sensor and knock sensor checked. Also clean your throttle body. Good luck!