Hello Everyone,
this has been an ongoing issue, I've been working on it at NASIOC but not getting too far with it so I thought I would try another forum.
I drive a 2002 Impreza TS. Over the past 2 months, it has been misfiring when starting. It clears up on it's own ater about 10 seconds and only does it when it's cold. Runs like a champ otherwise.
Things I have done so far:
Checked the plugs
Replaced the wires (two wires had very high resistance (cylinders 3 and 4) cyclinder 2 was above spec but not overly high, cylinder 1 was within spec.
Cleaned the IACV
Metered the Ignition Coil (input pins 1 and 2 had high resistance, around 2mohms, all other combinations were open) Output 3 and 4 metered approximately 13.6kohms while 1/2 metered 12.5kohms)
Checked for a leaking injector (did so by letting the car sit and pulling the plugs to check for the presence of moisture/smell)
Exhaust for smoke/smell (smells bad, but does not emit white or blueish smoke nor does it smell sweet)
The misfire has been isolated to cylinder 3 and 4. Only one at a time. Codes thrown have been p0304, p0303, and p0420. The 0420 popped up with the 0304.
The car ahs also been having issues with the heat going in and out and overheating. I believe this is all under control now and is not of primary concern. That said, On Saturday the car overheated and boiled over. The following morning, it would not start. I reset the ECU and it started up fine. Ran well all day and started this morning. Now, it will not start again. It cranks and attempts to turn over but never quite makes it...It backfires every now and then....I'm leaning towards an ignition coil, but I'm not entirely sure and I don't want to throw $150 at it if that's not the problem.
The headgaskets were replaced about 12000 miles ago and the car has 77k on it.
Thank you