Been trying to track down this problem since I bought it 1.5 years ago.

Description- Missfire anywhere from 4500-5700 rpm and does it about 50% of the time in any gear.
-New Optispark
-wires have 10k on them
-coil is a msd blaster
-Not sure on plugs-bought some ngk tr-55 not put in yet
-new fuel filter
-good fuel pressure at idle

*What else should I check? Any ideas on whats causing this? Any help would be great!

-andy

 

Try cleaning your mass air flow sensor with some alcohol. It may be dirty and causing your misfire.

 

thanks, any other thoughts?

 

could be fuel filter also

 

Just changed fuel filter and it has good fuel pressure at idle.

 

is it only happens when hot?

 

actually now that I think about it... yes. It seems right after i pull it out and not quite up to operating temps there is no missfire. Ill take it out tonight and test this again. Thanks

 

I just took it out and while it was cold it did not missfire once but when it got hot I would say half the time it missfired.

 

I just put a new optispark on mine tonight and now it missfires really bad. From about 3500 on up. It seems worse when I hook up my Mallory ignition but even without it it still does it.

 

optispark wire harness cooked?

 

have your ignition control module tested at autozone?

 

Did you check your air filter, I forgot to change mine and it started missing randomly at high rpms lol

EDIT: since you have CAI it would be
did you clean your air filter.