I have a 2001 impala, 3.8 li, 120,000M. It's not throwing a trouble code, but the car hesitates/stutters on acceleration. And this seems to cause a delay in shifting the transmission into gear. When it does shift it seems to shift solid. But as you drive, it may suddenly downshift and upshift. Seems like you need to rev the engine higher to get it to shift. If you accelerate too quickly it will stutter like it's chocking for air or gas. The engine runs smooth at idle or once you get going at a constant speed, 30-50 mph.
I don't think it's the transmission. I was thinking it could be something that regulates shifting of the transmission. That would account for the delayed shifting, but not the stutter/chocking. I read someone had a similar problem and they fixed it by replacing the catalytic converter. Could that be it? How about the plugs, coils, air intake, or fuel? Would any of these still allow for smooth idle and smooth 30-50 mph operating speeds? Why the delay in transmission shifting, and unexpected downshifting? And what does shifting have to do with stuttering/choking?
I don't think it's the transmission. I was thinking it could be something that regulates shifting of the transmission. That would account for the delayed shifting, but not the stutter/chocking. I read someone had a similar problem and they fixed it by replacing the catalytic converter. Could that be it? How about the plugs, coils, air intake, or fuel? Would any of these still allow for smooth idle and smooth 30-50 mph operating speeds? Why the delay in transmission shifting, and unexpected downshifting? And what does shifting have to do with stuttering/choking?
Oct 26, 2009 at 3:02 AM