I haven't run a test to determine specifically if this is the problem with my 96 Riviera, but a mechanic I work with thinks it is the problem. My car will start fine in the mornings, but once it gets hot, it has trouble starting. If I run arrends, I have to wait for hours to let the engine cool. I'll be honest, I don't know a lot about cars. However, everything I've read suggests that the camshaft position sensor is dead and needs replaced. Is this difficult or is it something an amatuer can do? I appreciate your help. Thanks.