Michael Dunne

hi, i have been chasing a misfire on boost problem lately and noticed today there is around a 3" chunk of the crank pulley missing exactly where the crank sensor would get its signal from,theres at least 1 lug missing.
it will be changed anyway but could this be the cause of my misfire on boost problem ?
if not what symptoms should it give ?

Michael Dunne

after having a better look the huge chunk missing is between 2 of the 4 lugs so all 4 lugs are still present.
would this chunk missing cause running problems ? obviously the sensor picks up on the 4 lugs but does it pick up on the parts inbetween the lugs too ?
the pulley is possibly a bit battered and dented too where it looks like someone maybe had a pain to remove it previously.
if this less than brilliant pulley/sensor issue would not cause my missifire on boost problem then i would rather leave it until i have fixed that problem.

Michael Dunne

here is a pic

london_chris

if the lugs are all present then it shouldn't present a problem as the ecu will know the position of the crank angle.

if it did it would be a continual misfire and not just on boost.

Michael Dunne

ah ok thanks, it runs fine until it tries to boost then hesitates violently and backfires.

Caddyshack

I would start with the very basics, new plugs and properly gapped and overhall the distributor.

Doesn't the crank sensors read the gap in the pully so if bits were missing it might false read but agree it would do it all the time.

My Cossie used to pop and bang and misfire. We changed the loom, ecu and now it is like any new car off the production line.

The engine looms do degrade and may well be causing issues too.