Expert: Paul Cunningham - 6/22/2007

Question
I have a 1991 Buick Regal 3800 series with 140,000 miles.  My mechanic informed me last year that the cam shaft magnet is misplaced.  I have been driving the car like this for 8 months as I don't want to put any more money into the car, and was told the labor alone would be expensive.
What can I expect to happen with the car?  Will it eventually just shut down?
A friend told me that newer cars just don't work when this happens, he thought it was funny that my car is so old it still works.

Answer
The Camshaft Position (CMP) sensor detects the position of the camshaft. The CMP sensor identifies when piston No. 1 is on its compression stroke. A signal is then sent to the Powertrain Control Module (PCM) and used for synchronizing the firing of sequential fuel injectors. The Coil On Plug (COP) Ignition applications (Taurus SHO, Mark VIII, 5.4L Expedition/Navigator, 5.4L E/F Series, and 6.8L Econoline) also use the CMP signal to select the proper ignition coil to fire. The input circuit to the PCM is referred to as the Camshaft Position (CMP) input or circuit.
It could begin to be hard starting. If that happens, just get a new magnet.