i've got a b18c1 in my del sol, with a turbo on it, was tuning it the other day when the tach started bouncing around at 5k rpms in WOT. REPLACED THE DISTRIBUTOR, and it's still bouncing tach and now it's started misfiring while WOT around 5k rpms. the ecu is good, we put it in another car and it runs fine, we replaced the wires, looked at the spark plugs, and now we're out of ideas.
A/F ratio looks fine also.
anyone have any ideas/suggestions?

 

does it miss at idle at all?

 

loose connection in wiring harness between ecu and distributor. there is 1 wire that carries a 12v signal to enable the ignitor in the distributor.

start at the connector that hooks up the distributor and check continuity all the way back to the ecu plug. wiggle it around and you'll find the connection is intermittent, assuming everything you're assuming so far is true.

 

there's no missing at idle. i'll run some continuity checks if i can find the ecu pin outs and whatnot.

 

higher revs = more vibes. a specific rev range will resonate with whatever part is causing the disconnection.

 

the ground wire on the top of the tranny was poorly connected.