89 sable 3.0. It only does this when hot. I shut the car off for 15 minutes to an hour. When i go back to start it again it will run real ruff for bit and then smooth out. Does anyone know what this might be. The car has had this problem since I got it.
I inherited the same problem recently after after cleaned TB and IAC + MAF. I replaced IAC but didn't really help. Then I adjusted the screw under accelerator cable, it helped a lot. But, again if I turn the cold engine on, idles ruff and smooths out like 20-35 seconds. BEfore the TB cleaning, it wasn't like this. There is no drivability issue, only when idling in park.
When I start it when cold it runs great. The problem only comes after driving around for an hour shutting the engine off for 30 mins or so and starting it back up again. It will act like it's flooded. In fact I'm sure it is flooded cause I am able to smell fuel too.