Fizzboy7

I have had the carbon buildup issue for most of my car's life, and recently had the pistons replaced. That got rid of the almost stalling issue after coming to a stop, but I still have a rough idle a few miles per hour before the car comes to a complete stop. What's a bit more strange is the same rough idle momentarily kicks in when I use accessories for the car. This includes the turn signal, power windows, or other things that draw power. What would one conclude is going on here? Could this still be related to carbon buildup even with brand new pistons, or is something else wacked, like spark plugs, etc?

amw896

This is the second post ive seen about this recently but i cant seem to find the other post now. I would say have your battery and alternator inspected as it definitely sounds electrical related.

robtwo

Every now and again when I start the car warm and the AC puts a lot of load on the motor I get a slightly rough idle.

I figure I might have to relearn idle on the car from cold.

Gville350

iTrader: (10)

After you had the car into Lexus for that repair, have you disconnected the battery to force the car to reset and re-learn everything? If not, I'd highly recommend it. Perhaps some MAF cleaner spray too.

Fizzboy7

I'm going to have to search for that. Very interested in what that may have been.

Fizzboy7

Oddly, my idle smooths out with the A/C on. I guess it's the constant higher rpm.

When I got the car back after the piston/engine rebuild, all my settings were still there. But the battery/alternator idea is worth checking. Thanks for your input.

Gville350

iTrader: (10)

^They didn't disconnect the battery when replacing the pistons (aka, removing the entire motor)? WOW!