I have a very similar problem to the one posted. I have a 01 Chevy Malibu Ls with about 102,000 miles. Automatic trans, 3.1L. The same thing occurs to my car when I am traveling about 65mph with the cruise control. I just had the Fuel pump and fuel filter replaced with a GM fuel pump. It revs slightly at high speeds. I can noticably see the RPMs in third gear fluctuate slowly from 2,000 RPM to about 2,300 RPM. The Service Engine light came on briefly and the service code was given as a low fuel mixture on bank 1. I thought the replacing of the fuel pump would fix the problem but it didn't. The mechanic I took it to also sprayed some carb clean in the engine compartment while it was on to see if it would rev. It didn't. I assumed it would be an intake leak somewhere but I don't think that is a cause at this point anymore.
Wednesday, September 5th, 2007 AT 4:08 PM