toast

Long time lurker here with a problem.

Got a 2002 WRX wagon with no engine mods that suddenly last night started flashing it's CEL while idling rough. Comes and goes, but is pretty constant. When I check the code, it's a misfire on cylinder one.

Funny thing is that I just replaced the belts. The clutch on the air conditioner compressor was making a 'sneezing' sound when engaging, so I tightened the belt a little more (but not excessively, did it to specs, seemed a touch loose) to see if it would clear it up, and wham, I get the engine misfires.

So while I'm thinking it's a coil (it got new plugs three months ago) or a wire, and I'll re-check that belt, what else should I be looking for?

Or should I just be looking for a good shop in the east bay?

ipozestu

iTrader: (18)

Unlikly it is a coil/wire. The solid state ignition system is very robust. Because it doesn't have any mods, doesn't mean it didn't have any mods. A misfire code can be difficult to diagnose. Without mapping your fuel trims, it's going to be even harder.

toast

Yeah, I know, but from reading stuff online it's one of the first things to look at. I saw on another board that someone had a simular problem and it turned out to be a loose wire on a coil. I'll be checking that all out today.

I'm the second owner of the car, had it for years now, and the guy I bought it from I trust to not have done anything with it. It was his driver, the guy races Porches and has a Radical, so the WRX was his grocery-getter LOL...

Only mods are to brakes and a rear sway bar (well other than stuff like K&N filters and other very minor stuff). A friend of mine who rally races semi-pro talked me out of doing any engine mods before doing those things first, and by the time I did those mods I was happy with the engine (and had a '67 dodge to wrench on now) anyways so...

Yeah, all I've got is a code reader. If I can't figure it out this weekend I'll take it over to a shop. Just wondering if there is other obvious stuff I should be looking for...

Mulder

Definitely check the coil pack first. Look for a loose attachment bolt, also remove the coil and look it over for any signs of arcing or cracks. If you don't see anything obvious, for diagnostic purposes you can swap that coil with one from another cylinder and see if the problem moves.
With the coil-on-plug setup there are no plug wires.
Even though the plugs are new it's a good idea to pull them and take a look. That one could have been gapped improperly or damaged during installation.
Last but not least, if you can't find anything by doing the above then perform a compression test. Low compression in a cylinder from ring or valve problems can cause misfires and set codes.

toast

Back in, with an update. Just finished doing that. Pulled the plug, it looked fine, checked the gap, it was a little out but not too much but I re-gapped it anyways, then I pulled the coil, it looked fine, but I swapped it with the #2 coil anyways and then started it up.

Problems still there, flashing CEL, cylinder #1. Boo!

Just the leads, yeah. Checked those just to be certain nothing is loose. Nothing is.

Don't have a compression tester, but I'm starting to think that this is gonna be more than I can fix this weekend. I'll drive it over to the shop on Monday and see how bad it is. I need the clutch looked at anyways, but still, this is probably gonna hurt.

Thanks everyone for the advice tho!

toast

Turns out it was the coil pack. Turns out that cylinder one isn't on the driver's side like I thought it was. Turns out I was a noob. LOL. But at least it was cheap.