1992 Olds 98 Regency trouble

Our old is driving us nuts :screwy:

When driving after a while the car starts hesitating and the check engine light comes on.
Reads code 41.
Replaced MAF and CAM sensor.
Didn't work.
Now it backfires too and blows black smoke sometimes too
After a few minutes of struggling trying to keep the car running it suddenly stops doing it and runs fine.
Sometimes it helps when we turn the car off and wait a few minutes before starting again.

What could it be ?

Thanks for the help.

Rob

Welcome to AF, If 41 persists suspect the magnet on the cam gear is gone, common problem, you may be able to see if it' s there through the access hole using a flex shaft shop mirror. There are other possibilities that are not related to 41, but start there.

I am in the middle of doing this procedure, so far so good you might want to take a look at it. http://bellsouthpwp.net/p/a/padgett46/cammag.htm
Good luck