Sierra 98 Code P1345

[Optech]

I bought a 98 GMC Sierra reg cab 4.3 auto with 163000 it runs good however it will not pass Indiana Emissions because the check engine light is on. It is code p1345 crankshaft position sensor/camshaft position sensor correlation. I can zero the code with the engine running with my code reader and it will stay off until you restart it and it goes on within 2 seconds. I have changed cam and crank sensor, distributor, cap, rotor, plugs, wires, gas filter, air filter, pcv valve and ignition module. The book tells me the crank sensor should be .050 from the reluctor ring. How is this measured?. Could it have a bad reluctor ring or is there to much play in the timming chain that could cause it. Any help is greatly appreciated. Both sensors are getting 12 volts to them.

[skippema]

I had a similar problem with my 96 5.0L. i had the distributor out of it and the timing was off a little bit. the check engine light would come on instantly. try checking the timing.

[Optech]

Originally Posted by skippema

I had a similar problem with my 96 5.0L. i had the distributor out of it and the timing was off a little bit. the check engine light would come on instantly. try checking the timing.

I took my truck apart and found the timing mark off by 1 tooth and the chain had over 5/8 play in it. I changed the gear set and zeroed the code and it worked. Hope this helps anyone with a similiar problem.