Light load/high RPM miss

[Bort62]

Alright, now that I actually have the thing driveable, I can start getting the small things knocked down.

The problem I am most obviously having to deal with is that I have a horrible miss above 2500 rpm or so - but...

Only In neutral or first gear. 2nd and 3rd pull through just fine.

Now, because I have a 4cyl T5 and 3.89 rear in a 2200 lbs car, higher RPM's in first gear is a pretty light load on the motor.

So that is the only correlation I can make between the problems in neutral and first gear.

So, I can't readily think of any ideas. It seems to be ignition related as most misses are. The engine is a 66 (200) block with 78 head. DSII (from kragens) upgrade using GM module and Accell Super Stock Coil.

I can't figure why I would only be getting the miss under light load unless it was vacuum related - but that still doesnt make sense. Is it possible the curve in my DSII is just totally screwed ?



Any Ideas?

Thanks.

 

[falcon60]

Good job getting the T5 swapped in,Ian. I wonder if retarding the timing a few degrees (like 5) and taking a test drive would tell you anything. Since it pulls ok at higher rpm in higher gears,maybe the amount of vac advance is just a bit more than it can stand in the lower gears and their lighter engine loads.

Terry