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Engine + Driveline / Rough idle, no power
« on: January 20, 2011, 11:25:13 PM »
I'd had a few instances before where the it would not settle at a good idle immediately on a cold start (would sit at very low revs and the warning lights wouldn't go out), but settle down properly with a quick blip of the throttle.
The car (1991 318is) ran perfectly fine yesterday. Idled like a champ, accelerated smoothly. Today however, it started to act up as soon as I started it.
The idle is rough, and the engine vibrates when revved, and there is very little power, as if one of the cylinders isn't firing properly. The check engine light flashes 1222 when I do the stomp test.
Disconnecting the #1 cylinder coil lead (I've switched to coil-on-plug) has no effect whatsoever on how the engine runs. Pulling any of the other coil leads, however, has the expected effect of making the engine run worse. This makes it obvious that cylinder #1 isn't doing much.
I checked resistances at the coil leads - almost no resistance between the outer leads, almost no continuity between either of the outer leads and the centre lead (I couldn't get a good enough reading to give you a number). There is no continuity between the leads and ground. This is the same for all the coils. I don't have my tools handy right now, so I can't pull the coils to measure between the leads and coil towers right now. Once I've done that, I'll post an update.
Any ideas? Could it be a clogged/dead #1 injector?
I should also mention that I had one hell of a time getting the thing past aircare last October, and even then it just squeaked through. I replaced all of the vacuum lines and intake gaskets during that episode. It's possible that I left a vacuum leak somewhere, but cylinder #1 not firing makes me doubt that. I sprayed all the injector's tips with carb medic when I replaced the intake manifold gaskets.
Thanks!
The car (1991 318is) ran perfectly fine yesterday. Idled like a champ, accelerated smoothly. Today however, it started to act up as soon as I started it.
The idle is rough, and the engine vibrates when revved, and there is very little power, as if one of the cylinders isn't firing properly. The check engine light flashes 1222 when I do the stomp test.
Disconnecting the #1 cylinder coil lead (I've switched to coil-on-plug) has no effect whatsoever on how the engine runs. Pulling any of the other coil leads, however, has the expected effect of making the engine run worse. This makes it obvious that cylinder #1 isn't doing much.
I checked resistances at the coil leads - almost no resistance between the outer leads, almost no continuity between either of the outer leads and the centre lead (I couldn't get a good enough reading to give you a number). There is no continuity between the leads and ground. This is the same for all the coils. I don't have my tools handy right now, so I can't pull the coils to measure between the leads and coil towers right now. Once I've done that, I'll post an update.
Any ideas? Could it be a clogged/dead #1 injector?
I should also mention that I had one hell of a time getting the thing past aircare last October, and even then it just squeaked through. I replaced all of the vacuum lines and intake gaskets during that episode. It's possible that I left a vacuum leak somewhere, but cylinder #1 not firing makes me doubt that. I sprayed all the injector's tips with carb medic when I replaced the intake manifold gaskets.
Thanks!
Please help me love my car again.
