Questions and Answers

Chevrolet Blazer Shifts Sloppily Q. Hi Mr. Ciulla, I am writing this for my very frustrated son. He has a 1999 Chevrolet Blazer, V-6, 4.3 liter engine, automatic transmission, fuel injection, ABS brakes, P/S, A/C, cruise control. It started acting up a couple of months ago. He has had it to three different mechanics and put on three different diagnostic machines, nothing is showing up.

The problem is the shifting, it is either slow and sloppy or fast and hard. Gas mileage has dropped 100 miles per tank. He has had the valve body replaced, problem showed up after this work was done. The fuel injector was cleaned, plugs and wires were replaced. The wheels move and can not be stopped when put in neutral. Can you help us figure out what the problem is and how we can fix it.

Thank you for your help,
Barbara

A. Were any codes stored in the PCM? Does the check engine light come on? If there is a transmission code stored, it will go into a default mode to protect itself from burning up. This mode will affect shift quality for sure.