Cylinder not firing

[schmidty]

took my e30 to the shop this mornin cause the engine was running and sounding like crap and they said it sounds like a cylinder isnt firing.

What do you guys suggest I do? Any common causes for a cylinder all of a sudden not firing anymore?

Im gonna try and take a look at the spark plugs this afternoon. Pull em out one buy one and see if there is any build up on the ends and seeing if they fire. I was told if they aren't firing the ends should be black and prolly will have some gas on em. If they are firing fine the ends should a brownish color correct?

Any other suggestions? Distributor cap/rotor maybe? I know two of my cams are pretty worn, could this be an issue?

TIA
Ryan

[NC325iC]

sounds like you need to get an m50... (thats not what i really suggest i just wanted to be the typical r3v suggestion guy)

check your plugs and get back to us

[schmidty]

sounds like you need to get an m50

that's my plan if the engine dies on me... but im hoping that doesnt happen for another year :p

[jlevie]

Any common causes for a cylinder all of a sudden not firing anymore?

Bad plug, bad ignition wire, bad distributor cap, failed injector, or failing DME are the most common causes of a mis-firing cylinder. But loss of compression from worn out rings, blown head gasket, broken rocker, or burned valves are also possible causes.

Obviously one starts with the simple cheap stuff (new plugs, wires, rotor, and cap) and valve adjustment. If that doesn't cure the problem and you prove that the injector is firing and delivering fuel a compression and leakdown test would be the next step.

[Mossman]

you can also unplug the spark plugs 1 at a time while its running, you should hear a difference with every one you unplug except obviously if 1 isn't firing anyways, no change = bad cylinder

[mode]

Could be a broken intake rocker arm.

[schmidty]

heres a stupid question for you guys?
my spark plugs FINALLY came in the mail (Bosch Supers).
The end that connects to the wires had a little metal piece threaded onto it. The old ones didnt.
I'm guessing the metal piece is for applications on other engines that might have a larger connector/boot?

Regardless, one boot doesnt seem to be fitting on the spark plug as snuggly as the others which is really annoying but prolly not the cause of my problems.

on another note: I had replaced the wires last week and that seemed to help some by itself. Until my tank ran pretty much to empty and it started running like arse again. idk what that was about (bad gas at the bottom of the tank maybe) but once I filled up it ran better again.


I have this ill feeling that my m20 is getting very tired and worn out. It ticks like mad even after a valve adjustment (one of the cam lobes is worn). I have a host of other noises that I keep hearing and have no idea what is causing them... and right now I can't afford to put a lot of time or money into her.... I just hope she makes it till the spring! :(

[strad]

Just about every spark plug I've ever purchased has that extra screw-on piece. I don't think any of my applications have needed it except maybe the lawnmower. Pretty sure my M20 didn't need it. The key is to compare old vs. new and make them look the same before installation.

I assume you're talking cam lobes, not cams. . .

[schmidty]

I assume you're talking cam lobes, not cams. . .

yeah, sorry (and edited original post for clarification)