D13 Is Idling High

When im idling My volvo 670 with d13 engine It will idling fine (600 rpm) then all of sudden rev up to about 1100. If I tap the clutch or release the parking brake it will stop and go back to normal until i take foot off clutch or set brake again then it goes back to 1100. Anyone got an idea?

Read your manual,there is usually a setting for idle,which can be controlled by using a combination,of the cruise control switches. This is used to build up air pressure in the brake system,and a few other uses.

It may be trying to run an active regen cycle. If it does that while you're parked, and you have an hour or more before you have to be rolling again, hit the manual parked regen switch and hold it for about 5 seconds. If your truck is trying to regen, the RPMs should pop up another 200 or so, and stay there for a good 45 minutes to an hour. Don't interfere with it, it's raising the temperature in the exhaust system to burn off excess diesel particulates. Just make sure you're not parked on or near any tall grass when you're doing it, or you're all but guaranteed to set off a brush fire.

Check your idle control, you hit one of the buttons.