Background: 135k, 25mpg, no noise, no vibes (other than what I attribute to operating on the "limp home map"), good starting (given operating map), good acceleration except for slight stumble/hesitation (operating map).
I have a 1991 Park Ave that triggered a check engine light recently. The code was 041 (if I remember correctly) which I was told is the code for trouble with the cam position sensor. I bought a cheap sensor at the local Autozone to see if I had an easy fix on my hands. To my surprise, the existing sensor had been beautifully machined by, I assume, the magnet button on the cam sprocket. Because the abrasion was so nice, I am led to believe that the magnet and sprocket are secure relative to the cam. I looked at a new replacement cam gear at the local NAPA, and saw that the magnet is installed from the rear of the sprocket and could not move closer to the sensor unless, 1) the sprocket was loose (which would likely show other symptoms) or 2) the whole camshaft moved closer to the sensor. I have plans to replace the timing set and magnet, which I feel confident will cure the error code, but I would like to get an idea of what to expect in terms of axially repositioning the cam, if this is the cause of the problem.
Does anyone know how the cam is held in position? Does anyone know where I could look at a schematic of the engine (besides the dealership)?
Thanks, John