View Full Version : Crankshaft position sensor

07-05-2017, 05:14 PM
I hope I haven't double posted but I seem to have messed up the first time so...
My friend has an 89 SC that idles like it has a full race cam in it and misfires like a son-of-a-gun under throttle.
He had the front main seal replaced a few years back and this is when the trouble started. They tried and failed to fix it.
Apparently the mech had to heat the balancer bolt for a long time to get it to loosen. The mech called my friend after he finally picked it up to tell him about the heating process. The crank sensor looks unscathed so I think they removed it before heating. Is there anything behind the balancer that can cause poor running if damaged by heat or is there a tool they should have used to line up the crankshaft sensor. I also had the sensor off to check it so I would have installed it in the wrong position too if a special tool is needed.
It's been sitting a couple of years since I worked on it so a fuel system flush will be needed too, but it's off the beaten path so I would like a few good ideas to go with.
Thanks for any info, Wally

07-05-2017, 05:50 PM
Anyone connected a code reader?

Does the tach drop and then recover?

Does it take more than one stab to start?

07-05-2017, 08:14 PM
Maybe he should double check the plug wires where they're attached at the coil pack. This is an extremely common mistake and it wouldn't surprise me 1 bit if some shop mechanic bungled it.


654 :eek:

sam jones
07-05-2017, 08:27 PM
Good evening

After checking for codes inspect the crank sensor air gap. Use search. Example: http://www.sccoa.com/forums/showthread.php?137617-Changing-Crank-Position-Sensor. The mechanic may have disturbed or worst case damaged the clearance when reinstalling the harmonic balancer.

Good Luck.