Misfire/Surging and No Power

[1987 Grand National]

My '87 GN with recently replaced cam(because it wiped the original) is bucking like an ignition problem and can't get out of it's own way. I have replaced the ICM and coil pack. No change. Also tested a known good pair from another car. New crank position sensor. TPS voltage looks good and smooth through out. MAF is at a 05 at idle. I have unplugged the MAF and Cam sensor while it was running with no real change. I don't feel the cam has been installed incorrectly. If it were I figured it would just be a turd and not have a surging problem. When I rev it in park it doesn't have a miss but it does seem to rev slower than before cam. Also the miss/surging problem did exist prior to doing the new cam. What do you guys think?

 

[TurboBuRick]

Sounds like crank sensor got smacked. How did you set it? If the wheel has made contact with the sensor, it's junk.

What brand sensor? Did you replace bracket too? Stock balancer? Stock crank?

These cars are very sensitive to the crank sensor.I find it necessary to modify brackets to add clearance on some cars. Specially ones with aftermarket cranks and balancers. The blades that pass through the sensor run too deep. Or the senor is not square to the wheel and the tips of the blades smack the sensor. Take a close look at these possibility's.

Also I have the best luck with AC Delce sensors. Part # 213-292. Need bracket # 213-280 as well. The Brackets are now discontinued but you can still find them on the net. Sensors are still available.

HTH

Rick