Engine Misfiring

[city998]

I have a recent problem with my 998 engine. At times it misses a beat intermittently. When warm, under hard acceleration (up a hill or accelerating on the flat) it can feel almost like it's running out of fuel. I set the timing last weekend but dwell is 59° - 60° vs a spec of 54° with a tolerance of 5°. Is that likely to be contributing to the misfire or should I be looking at the SU? Any ideas?

[just_st3v3n]

just something to check happened on my mini and had the same sort of effect your talking about:
check to see that the fuel pipe isnt touching of the manifold, was the case in mine and the harder the engine worked the hotter the manifold got and basicly evaporated most of the fuel before it got to the engine....

steven

[woody]

The dwell angle isn't to far out and only becomes critical at high revs but if you have a dwell meter why not set it correct. Have you checked the oil level in the dashpot.

[city998]

Thanks, guys. My fuel line hasn't moved and isn't on the manifold so vapour lock is not a likely cause. I'll reset the dwell this weekend and think it may be a factor as I noticed today it does seem to occur at higher revs. It just seemed that more dwell=fatter spark so I wasn't looking at that the first time.

I'll post results when I have some to report!!