idle drops too low

[obx tsi]

when i push in my clutch to slow down my idle drops off to 0, my injp drops to 0 and car cuts off. why? car will restart with no problem.

 

[Shane2GSX]

Are you throwing a CEL?

 

[steve]

Normally the ECU sees that the car is moving when the throttle closes and uses the ISC to keep the engine running. Since yours doesn't I'd check the the VSS, IPS, and ISC to start with.

Steve

 

[obx tsi]

no cel's and my logger shows the isc change when speeding up and slowing down. i usually have a hard time navigating sites so if you could post a link that shows how to check the vss, and ips. my haynes manual is not very thorough so a better explanation would be helpful. thanks.

 

[steve]

The ECU has no way of knowing that the ISC is actually moving. The only clue it has that there is a problem is that the RPMs don't change as it tries to change the ISC steps. What you might see on the logger is that the steps go to 0 or 120 at idle.

Steve