HawkeyeXJ

I recently pulled my engine to replace rusted freeze plugs and the head gasket. Motor is back in place and running, but now surges in idle especially when warmed up to operating temperature. If I leave it idling it will eventually surge low enough that it will die. I've also had it die on me while making a turn at low rpm. CEL came back with the p1391 code, (camshaft sensor/ crankshaft sensor) which from my extensive research over the last few days seems to have a lot of options to troubleshoot.

Well I've only had these troubles since pulling the engine, and since this was my first time pulling an engine I figure it has to be something I damaged in the process. After researching how the crankshaft sensor works by magnetically reading the slots on the flex plate tone ring for timing, I realized how I most likely caused this problem.

While attempting to remove the flex plate from the crankshaft without an impact wrench, I was trying to figure out how to remove the bolts without turning the crankshaft. Being inexperienced and uninformed, I did a BIG no no and wedged a screwdriver against one of the bellhousing bolts and through one of those slots in the flex plate since I knew nothing of their purpose. Of course this tone ring slot couldn't handle the torque and buckled. I bent it back roughly into place with the screwdriver and didn't think anything of it.

Now with these problems I'm having, I am 90% sure that the slightly damaged slot is the issue (other 10% is that I maybe damaged the CPS while re-installing the engine.) I basically wanted to post on here to have somebody more knowledgeable than me confirm that I was indeed an idiot by jamming the screwdriver through the tone ring and that this will cause the p1391 code and idle issues.

Thanks for reading through this, and for any insight. Hopefully this can help somebody else in the future to not make the stupid mistake that I'm pretty sure I made.

Radi

I'm guessing you are correct, that was enough to alter the CPS readings and confuse the computer.