Everthing was fine for several months after purchasing this used. Engine suddenly started running very poorly. Hard to start, would barely idle, stalled a lot, bucked and sputtered regardless of gas pedal position/movement. Sprayed starting fluid into the throttle body-nothing. Starter works fine. Battery in good condition. Camshaft sensor reads good according to (MT2500) scanner. Crankshaft sensor bad. New crankshaft sensor made no difference. Still reads intermittant. All other scanner functions and tests on this Caravan check out OK

Does anybody know what the timing holes/notches should look like in the flexplate ? I managed to look into the crankshaft sensor hole with difficulty, a mirror and a flashlight. Rotated the engine a little at a time through one full revolution. I looked to see if anything was obviously wrong. I saw one through-hole then several other holes that did not go through, spaced 1/4" to 1/2" apart. These looked like a piece was in back of the holes blocking them. Aren't all the holes supposed to go all the way through ?

It's a 1994 Grand Caravan AWD 3.3 engine.

 

The square holes are space out to trigger the crank sensor or a snap shot. If the flex plate is cracked, that will throw the snap shot off and cause either a loss of crank or cam signal.

 

Yes, I saw the square holes. What I'm wondering about is if all of them are supposed to be through-holes. Most are not through-holes on this flexplate. Is that how it's supposed to be ?