Angry73

I have an 5.3 swapped 1973 Camaro and I redid the wiring harness after it was halfassed by someone other than me. Before I redid the harness the car ran great but after not so much. I've been getting a P0342 code and very hard starting. I usually start my car two times, to school and after school. The first start up is always very hard, but the second is very quick and how it should be. Sometimes it's vice versa. Car idles somewhat fine and runs okay but not perfect. I have checked the plug at the cam sensor and it got around 11 volts on the signal and power wire. So then I changed the sensor and it didn't really help. I checked to see if the pins were in the right location which they were so now I'm clueless. It has power, new sensor, and it's all plugged in but still starts like a bitch. I'm beginning to think its mechanical but I'm about 75% sure nothing has been done other than intake and injectors.

Any help or suggestions are greatly appreciated
-Jesse

Blasphemy

I've been scanning through a few threads on here because I'm having the same DTC issue. The main difference I've been seeing is that almost everybody complains of hard starting but my engine starts instantly as it always has. What it's doing is misfiring at idle, accelerating, and low load driving speeds with the occasional backfire. People are saying that it's likely not the sensor but it could be somewhere in the connector or wiring. If you did harness work I would check all wiring going back to the pcm and verify that you have good connection with little to no resistance. I also bought a brand new sensor with no change whatsoever. I'll verify wiring and connection today and get back to you if there is an improvement

Chevy406

iTrader: (12)

The cam position sensor is only used during cranking to tell the ECM which cylinder is coming up on compression and ready to fire a spark. With a failed cam sensor signal, the ECM has to keep trying different times to fire the coils until it gets the correct cylinder. So sometimes the engine will start correctly and other times you have to crank for a while.

Failures that can trigger the cam position sensor codes can be the sensor, the connector, wiring, or something affecting the sensor like the rear cam bearing slipped back.

If you have a scanner that shows live data, set it up to read cam position voltage. Either pull the sensor out or use a known good sensor that is plugged into the harness. Test the sensor, wiring, and ECM by moving the sensor past a metal object and note reading changes on the scanner. You will have to hold the sensor very close to the metal. If the sensor, wiring , and ECM pass that test, then you might have something going on with the cam shaft or possibly something in the engine too close to the sensor and causing a false signal.