High idle

CMZANNN

MEMBER
1986 HONDA ACCORD
4 CYL
FWD
AUTOMATIC
200,000 MILES

1986 honda accord lxi 2.0 the car always idled@under 1ooorpm. Since I starterd "messing " with cruise control idle has risen dramaticallyi-13. Sometimes when I throw it in park &leave it running 14 or 15 aint out of question. In my remiedial searches for soultion to this dilemea?Is not there a rpm. Something control assoc.W/cruise control s--t clustred in all the high tech c. Ctrl?Dont think it is any sensor etc. Can I get some expertise please. You people do a superb job which I think is the best site on web !No s--t thanx

1 Reply

CARADIODOC

MECHANIC
33,874 POSTS

Sounds like you have a vacuum leak. The cruise control servo is run by engine vacuum so whatever you "messed" with, I suspect you left a vacuum hose disconnected. It will be a small hose, often originating from a tap on the power brake booster check valve. Otherwise it will come right off the intake manifold. There should be a sticker under the hood showing the vacuum hose routing and it should show the servo.

You can also search for all of the vacuum hoses coming off the intake manifold and pinch them closed one at a time. When you find one that brings the idle speed down, follow it to any tees, then pinch off each branch to figure out which one to follow. Keep going down that hose until you find one that's disconnected or cracked.