amirpc

I'm driving my new 951 home to TX from NY right now and there is an annoying attempt to stall happening at low gears. Basically I'll disengage the clutch while going slow to go from first to second or vice versa and the RPMs will plummet quickly to almost 0 and the car feels like it is going to stall. It did in fact stall here once. Then the RPMs climb back up to idle around 900. It is a problem in stop and go traffic because I am constantly trying to prevent the car from stalling.

Does anyone have ideas about what this could be? My only thought is vacuum leak somewhere.

amirpc

Just spent 15 minutes spraying carb cleaner at the vacuum connections listening for surging and couldn't find anything. Now really have no idea.

One thing is it doesn't happen at idle, only between shifts. It idles smooth, if a little high (cold idle at 1100).

Humboldtgrin

Sounds like the idle control valve is a little slow when you let your foot off the gas pedal to shift. I would check it. Then look for that idle screw on top of the throttle body, make sure the o ring is still good. Could just be a little gunk built up in the IAC valve that is slowing down its performance. Clean it out with carb cleaner and reinstall it. See if that makes a difference. Also while you under the intake check the brake booster venturi (that grey "Y" plastic piece), both of my cars had them come apart creating a small vaccum leak and made my brake pedal stiff. I just super glued them back together and it works great.