Problems with my 1997 Buick Riviera

Just recently got my 97 Riviera with the L67 back on the road she has 107k miles and the previous owner was a WWII vet who babied and garaged her from new. In 2019 on his way home from getting the trans rebuilt he pulled out in traffic and got the front mopped clean off (car had 2 miles more than the shops receipt shows). In 2022 after sitting covered for 2 years I acquired the car and a $500 parts car. About a year of work later she back driving with one issue.

The codes I am getting now are a P0302 (Cylinder 2 Misfire) and a P0341 (Cam Position Sensor). I replaced the Cam Sensor with a new working one and the code will appear sporadically after the repair, so I don’t believe it to be the issue however maybe it’s a clue. I have chased the misfire to the extent of my knowledge bringing me here. I replaced all 6 plugs and put an all-new set of wires on. Swapped the coil packs with known working ones with no luck. Tested the fuel pressure and it all looked good. Swapped the PCM from the parts car and the problem is still there. Also tested for leaks in the cylinder 2 injector but found nothing.

As far as how it feels the problem appears to be sporadic. The main time that I can notice it is when the car is idling. You can see the rpms fluctuate but this is not every time the car is idle, I would say about ¾ of the time it behaves like this. Also, twice I have gotten a blinking check engine light on startup which I found online is cat failure due to a misfire maybe but maybe its another clue who knows.

Any ideas would be greatly appreciated and if anyone wants or needs any more information just let me know.

At that milieage the crankshaft position sensor could also be failing.

IIRC the camshaft position sensor detects a little magnet on the camshaft, and it's possible for the magnet to fall off. I haven't been that deep into the motor myself, but I remember seeing the comment.

Welcome to quarter-century old car ownership!

I had a chased  this problem with my 99. Turned out to be a broken wire inside the plastic coming out of the main bulkhead connector under the brake booster. Took me two years but the car runs so much better.

The infamous "black wire?"

https://rivperformance.editboard.com/t4703p175-faq-p0341-camshaft-position-sensor-cam-sensor-timing-chain?highlight=P0341

Scroll down to my post, and start there.

Pretty much, I remember Larry telling me about it as well.

I took of the connector as described out comes this.

carguy8888 wrote:

I had a chased  this problem with my 99. Turned  out to be a broken wire inside the plastic coming out of the main bulkhead connector under the brake booster. Took me two years but the car runs so much better.

This is a GREAT example of how folks should check the simple stuff!!   I had a friend who was ready to put a whole new injection system in his Suburban, and when I analyzed it I found a simple coil primary wire that must have been "crimped" when the motor was installed in the body and was finally causing an intermittent connection...   $10 Fix!!!