Code p03041 cam position sensor

[th3 shifty]

Having this issue with the cam position sensor.
History of work done: I have changed the timing chain and made sure the dots lined up, I also changed the crank position sensor and O ring while I had the truck front end off. Last year I already converted to MPFI and changed the cap and rotor and it was running great.

I changed the timing gear as a “while you’re in there”.. since I was doing the gaskets for the timing cover, oil pan, and water pump. Never touched the timing or distributor.

Cut to yesterday I had previously started the truck many timing, it always idled at 800rpms and seemed to sound good. I would let it idle about 2-4min at time just to check for leaks and to cycle all the fluids during the resto. I start the truck.. starts just fine and idles well.. I get about 2 miles down the road and it starts to get rough.. and dies at a stop light after sitting there for 2more minutes. Pull code P0341 only. I bought a new sensor from Autozone, put it in today.. cleared the code, started up great, idled just fine.. let it idle for 10min… gave a few revs to 2500.. everything looked good.. go to back out, stumbles a bit.. then rough idle like before.. pull back in and shut it down. No code.. started again and it’s rough and set code p0341 again ..

Thoughts?

 

[Eman85]

Did you check distributor offset with a scan tool?

 

[th3 shifty]

I have a Foxwell 510, not sure if it can read the advance and retard of the cam

 

[east302]

The GM manual (1998 shown) implies that a wiring defect or being too close to electrical interference such as spark plug wires could be a cause.

Getting the CMP offset set with a scanner would be required since you pulled the distributor.

 

[th3 shifty]

No I didn’t pull the distributor. You can change the sensor without pulling it

 

[th3 shifty]

Only thing with timing I can read with my scanner is spark advance seen here:

 

[east302]

No I didn’t pull the distributor. You can change the sensor without pulling it

Sorry, I had a senior moment and misread your post there. The spark advance wouldn’t be what you’re looking for - it would be labeled CMP Retard or maybe CMP/CKP Correlation.

I haven’t had the issue myself, but others have seen that code pop with a worn distributor gear. Do you have oil pressure while cranking?

 

[th3 shifty]

The motor kicks over in about 1 second, super fast. Oil pressure rises pretty quickly

 

[th3 shifty]

Ok so I read that the cam and crank position sensors work hand in hand.. looks like I never replaced the crank pos sensor, I just replaced the O ring.. and looks like I didn’t have the spacer on it either. There was a moderate amount of debris on the face of the sensor as well. Going to replace the crank pos sensor and see what that does

 

[east302]

Do you have any other codes?

It looks like the P0341 is flagging an intermittent issue with cam sensor signal voltage. I’m not sure where you’d tap it, but if your scanner graphed the signal voltage it would probably show inconsistent oscillation. That could just be a poor connection or some intermittent wiring issue (rather than a permanent short and complete loss of signal) or something upstream (bad distributor gear?) causing the sensor to read erratically.

Here is the pinout for the Blue C1 connector at the VCM. The signal voltage is circuit 633, pin 3. I’d check the connector and try to trace the harness back to the cam sensor. Maybe something will stand out.

The ENG1 fuse isn’t blown is it?

Aggravating, for sure.