Starting issue - maybe cam sensor?

[hesermon]

When cranking to start it will turn over normally then suddenly stop almost like the motor is locked. Release the key, try again and it turns over fine. If it doesn't start on the first several cranks it stops again (sometimes with a very small backfire or more like a cough through the exhaust). After 2 or 3 tries it starts and runs great. Since it runs fine once it starts I'm thinking the cam sensor is going bad? This is on a I/C converted 85 done over a year ago and this problem is new, the cam sensor from the donor 87 was damaged so I'm using my original that came from this motor. Currently has 50K miles with no other issues. Am I on the right track here? Other ideas? Thanks in advance!

 

[S10xGN]

Pull the cap and check that the reluctor wheel is not sheared. If it's good, reassemble it then try twisting the whole sensor a few degrees in whatever direction helps.

 

[hesermon]

Pull the cap and check that the reluctor wheel is not sheared. If it's good, reassemble it then try twisting the whole sensor a few degrees in whatever direction helps.

Just saw your reply and can't get to the car right now, are you saying you think I'm on the right track with the cam sensor?
Hugh

 

[S10xGN]

Mine exhibited the exact same problems when it was off a bit. The wheel was fine, the sensor just needed a slight twist...