Weird situation going on here lately.

Over the past month and a half the car has randomly shut off coming to a stop light. I also noticed a few times today that when I clutch in but keep the car in gear while moving the idle will drop to between 250 and 750 and bounce until I clutch out and keep going. 60,XXX on the clock.

Mods: JLT intake and SCT tuner.

Ideas?

 

Clean the inside of the throttle body especially between the blade and the bore. The drive-by-wire TB doesn't have an idle air control valve so any dirt that accumulates between the blade and bore can play havoc with the idle quality.
You could also clean the MAF sensor while you're there.

 

I agree; most likely a dirty TB. I'd also give the MAF a good squirt of cleaner. When did you run a good fuel system cleaner thru the fuel tank? Seafoam and Techron are decent products. I run Techron about every 10k miles and Seafoam if I have an issue like yours.

 

Many 3v misfires have been solved by SeaFoam. Love the stuff, buy it by the gallon and use it on all the cars I maintain.

 

I've yet to run any fuel cleaner, only have had the car about 2 months now. Looks like I'm running to the parts store to get some sea foam.

 

I still suspect the TB needs a good cleaning. This would be the most likely reason for your problem but the SeaFoam or Techron is good to do as preventive maintenance regardless.

 

Haven't had a chance to clean anything yet, but damn thing died on me twice this morning. Looks like I'll be doing it today.

 

It'll only take you 10 minutes to clean the TB so what are you waiting for?

 

It not to rain due to the fact my garage is full. Meh.

Probably do it over lunch today at work.

 

Cleaned throttle body, MAF, added injector cleaner, and seafoamed. I did have it die once on me since, but it does SEEM a bit better. Will keep watching.

If this doesn't do the trick, what the hell is next?