M42 intermittently running on 3 cylinders - cold start
Posted: Fri Mar 19, 2010 3:01 pm
After a trip down to the Alps and back, my M42 intermittently starts from cold on what sounds like 3 cylinders. First time it did this was after being parked in -10c or less for 4 days, then again a few days after getting back from France.
In normal operation the starter will crank for 1-2 seconds before the engine fires. When this occurs, the engine will catch almost as soon as the key is turned. It comes back to 4 within a minute or two but idles a bit rough. Accepts throttle normally otherwise and appears to fire on all 4 from cold once throttle is actually applied. No smoking or noticeable oil or coolant contamination. Plugs are correct and new enough. Camchain probably needs doing (123k or so). No strange noises (other than the characteristic slight tick under load from ~3-4k which I attribute to the camchain, guides and sprockets needing replacement - tensioner's already been done).
Anyone had this or have any likely candidates for the source of the problem? Would rather sort at some point it before it gets worse rather than ignore.
In normal operation the starter will crank for 1-2 seconds before the engine fires. When this occurs, the engine will catch almost as soon as the key is turned. It comes back to 4 within a minute or two but idles a bit rough. Accepts throttle normally otherwise and appears to fire on all 4 from cold once throttle is actually applied. No smoking or noticeable oil or coolant contamination. Plugs are correct and new enough. Camchain probably needs doing (123k or so). No strange noises (other than the characteristic slight tick under load from ~3-4k which I attribute to the camchain, guides and sprockets needing replacement - tensioner's already been done).
Anyone had this or have any likely candidates for the source of the problem? Would rather sort at some point it before it gets worse rather than ignore.