I30 rough idle at start

[mmike87]

Hello, I have a 2000 I30 with 112k miles on it. After sitting for a day or so, when I start the car the idle feels slightly rough. When I put it in gear, there is no throttle response, and this AM it stalled.

Once I get going down the road after about 15 or 20 seconds it's fine all day. Smooth idle and no issues.

Any suggestions? Thanks!

[jltibbs]

adjust IACV up a little, clean MAF, run some fuel system cleaner, and use premium fuel only.

[mmike87]

The MAF was replaced about 10 months ago ... can they get dirty that quickly?

[mmike87]

Well, jltibbs - you called it. The dealer said the MAF was faulty, especially bad at cold startup. There was a code set for the car running lean ("135% alpha" whaever that means), so I imagine that the rough idle at startup was caused by the mixture being too lean (as I understand it engines typically run richer when cold...)

I also got the full transmission flush service as well, and the car seems to run great and shift are a bit smoother now.