RussianE39

Anyone got digital oscilloscope ? I can easily see spikes / random noise on TACHO output of PFC on subaru when misfire occurs, my experience tells me this is problem with crankshaft sensor sync.

I'm trying to fix that problem for about last 2 years, this is my opinions: 1) Problem is no way related to ignitior (at least on Subaru's) 2) In Subaru case PowerFC loses sync to camshaft / crankshaft sensors (In some very bad cases you could even see 16384rpm or smthing on Commander) 3) 90% of GC8 Ver 1-2 owners hadn't this problem when their PowerFC was new. 4) Some cars got it only on heavy load, under WOT etc, some cars got it only on light load. I think we should compare input schematic for crankshaft sensor from non-affected PowerFC units with our misfiring units - 99.9% the problem is here. 2PaulR33, I found link to this thread in your FAQ, but haven't seen fix by scott, please point me. Ah, sry, that ground for ignitior is just placebo in case of Subaru :-)

Hi from Subaru world, Power FC for Subaru Impreza GC8 Ver 1-2 have this problem too, it is totally random misfires, one of our customer splitted his crankshaft to two halves after that PowerFC misfires, the most interesting thing, that Power FC's for Ver 3-4 or Ver 5-6 Imprezas haven't that bug. We tried everything - even totally new engine wiring harness - no luck, on stock ECU it drives fine, on PowerFC - pop-pop-boom-misfire :-(