Quote:
Originally posted by 944 Ecology
This is a known problem, and Porsche put out a tech bulletin on it around 1989 or so.
It seems that the smaller (gear reduction) starter generates a stronger magnetic field when it is cranking, and stray magnetism fools the speed sensor into firing the ignition pulse on the compression stroke. This results in a "thud" and a halt in cranking for a second. The next few times that you attempt to start it, it may be just fine.
The fix is to retrofit the later flywheel sensor bracket and a shield for the speed sensor to stop that.
And, that's the way it is....
gb
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Wow thats interesting and I agree that it must have been difficult to find that!!!
How difficult is that to change out? It doesnt sound too bad.
Another thing I was wondering is this... When I am crusiign along the highway at about 2900RPM or so and then I give it just a little bit extra throttle to accelerate slowly I notice that the tach twitches a little bit. It twitches about 100-200RPM up...is the engine trying to advance the timing too much and then backing off?
Thanks guys for all of the help!!!!