Im sorry if this isnt exactly third gen related but someone may have swapped an LT1 over and had the same problems my buddy is having.

My buddy has a 97 trans am with an LT1 and an automatic. We recently took a trip to nashville in it and on the way back, the metal part of the rotor inside the opti broke off of the plastic rotor and slung through the cap. The car backfired a few times and then completely died. After an extremely long wait we got the car towed back and found that problem. He put a new MSD cap and rotor on it and put it all back together and thought he fixed it. When he drove the car it ran like crap. Its almost like its in "Limp home mode." The car feels like your in a stock honda civic when you go full throttle and if you rev it up it backfires and makes a popping noise almost like it is backfiring out of the intake.

He had the codes checked the first time and the place that did it said the Mass Airflow Sensor had gone bad and so had the Crank Position Sensor. He replaced both and the car still runs like crap. I ran the codes for him and this is what I got:

P0100A- MAF Frequency Insuff Variation
P0335B- CKP circuit
P0336B- CKP Sens Circuit perf

The MAF And Crank Position sensor are both brand new. I checked all the grounds I could find and they are good. I cleared the codes 3 different times just to be sure and they came back everytime. It is still throwing the codes even after new sensors and unless both the new sensors are bad, Im thinkin its in the wiring or the ECU. Both of these problems started with the opti goin out. Has anyone had these problems with there LT1 or heard of them?

Any helpful input would be appreciated.

 

I bet that the optical sensor got damaged when it slug the rotor button.

 

Exactly what I was going to say. Go to O'Reilly's and get a life-time warrantied baseplate and optical pick-up for $99 and I just about guarantee it will fix the problem.

 

So he just needs to go get a new baseplate and optical pick-up for his optispark and it should be fine? My first experience with optisparks was on my car and I am still learning. I don't see why it wouldn't throw the opti code if it is messed up?

 

It won't unless it's misfiring on a cylinder. And to be honest, if he's planning on keeping the car, go ahead and buy the complete MSD unit. Yes it's about 200 more bucks than the stock one (I priced one at the Autozone where I work for around 200 bucks). But the MSD unit is a very sweet piece.