2.0 with a miss

[mejulihn]

My '76 2.0 has a noticeable miss between 2800-3200 rpm in all gears. I just had my local independent Porsche mechanic complete a full tune-up but the miss is still there. It is annoying because it interupts an otherwise smooth acceleration thru each gear. Anyone got some ideas??

[Joe Browne]

Is thia car F/I? If it is I'd check the throtle switch first.

I had cutout at that rpm too on my 1.7. It turned out to be ignition. I replaced the points and condenser with a breakerless ignition system. The timing mark at 3500 rpm with vacuum advance disabled could be set and forgotten. Before that, the timing would fluxuate from the v mark in the fan housing. The miss was eradicted. Diagnosing FI problems is a pain but vacuum pipe leaks are the most common problem and the cheapest to fix. Get the book How to tune and modify Bosch fuel injection systems. You'll learn how hardy D jetronic FI systems are.