I've been going crazy because of the service light, I've scanned the car several times looking for the code that I've cleared a few times........ and still pop's up, and it's always the same.
CKP Circuitry Malfunction, and the other one CKP Sensor. The CKP sensor it's new and also i've replaced the timing belt, distributor, ignition cap, rotor, coil, ignition module, and the last thing that's been changed was the plug (tip) for the wire that runs from the distributor cap to the ECU. Lately when I scan the car and ask for current codes on the scanner, comes up like there isn't any codes, but when you look for the history of codes there they are, and the service light ALWAYS ON. I don't know what else to do, what else to check or replace. Ran out of ideas.
If somebody can help me out it's gonna be really appreciated.

 

It's a 1996 Z28 And these are the codes:
P0335B-CKP Circuit, and P0336B-CKP Sens Circuit Perf.

 

if any gurus around, please help me out. it' driving me nuts.: freakout:

 

I get the P0336 from time to time. Seems like it only comes on if it the weather is on the warm side, and I've been sitting in traffic. I just clear it.

 

P0335 says missing pulses from Crankshaft Position Sensor CPS to PCM (50 out of 100 samples), P0336 says CPS signal count is not synchronized with opti low resolution pulses (camshaft position sensor). I would go after the P0335 first, figure out why pulses are not getting to the ECM. You feed +12 and gnd ref into the CPS and it sends +5V pulses to the PCM. Since you already replaced the CPS, get out the wire diagrams and verify the voltage, ground reference, and signal while wiggling the harness and connectors back to the PCM. In your OP I assume timing belt really means timing chain and distributor means opti. The CPS signal is triggered by a relucter wheel on the crank held in place by the hub, make sure your hub is not backed out causing the reluctor to be loose. http://shbox.com/1/engine_front_diagram.jpg . By the way you can reset all codes by disconnecting battery negative terminal for 5-10 mins. Or pulling +12 volt BAT fuse to the PCM.

 

Thanx for the info, and sorry about that, its timing chain and opti. Its been a while using other cars that run with timing belt and distributor. Gotta get used to those again.