Idle question

[Ray_Reed]

I have a 1993 Ford Ranger that idles fine while stopped and doesn't have a problem cruising down the road but when I press in the clutch while cruising I noticed it constantly idles slightly up and down every couple of seconds until I release the clutch and am back in gear...what gives?

 

[ForOffRoadDriving]

my 90' 2.3l does the same thing and it comes and goes, ive repaired some vaccum leaks and it goes away, but always comes back, so i either keep getting vaccum leaks or my truck has a mind of its own?

 

[Ray_Reed]

Anymore input on this problem???

 

[ForOffRoadDriving]

check the idle air control valve for build up around the pintle (the little stopper thats seals off the flow of air through the 2 holes), also check all your vaccum lines for leaks/ cracks. the only components i still have hooked up to the vaccum 'tree' are the brake booster, the fuel pressure regulator, and the heater control (blend door actuator i think?). everything else i ditched in order to make things less complicated. you can check for vaccum leaks using starting fluid by spraying it on the vaccum hoses and if the idle speed increases then youll know you have a leak where you sprayed. sometimes this works great and sometimes it doesnt help at all.