RPMs surge slightly when at steady speed
Explanation - between 30 and 65mph while keeping the speed and rpms as steady as possible I can see on the TAC that the rpms rise by about 100 or so and I can actually hear it through my flowmaster exhaust. For instance at 40mph and 1400rpm I can see the TAC go up to 1500 then back down again this continues about every few seconds. At idle the rpms are steady. Above 70 I don't see this, it starts around back when speed drops to around 65. Neither the SES or check engine light are on. Anything simple I can check?
99 Firebird V6 3.8 automatic 149k
Re: RPMs surge when at steady speed (Solved)
Pretty embarassing actually, my son who also drives a 99 Firebird suggested I change the air filter - that did the trick.
the air filter should not effect it. your issue is most likely engine misfiring. check the wires and plugs, and the box on top of engine where wires conect to. if this is the case, it will get frequent and you will see the SES light.
selling my jet chip if youre interested.