High Idle

[Green Monster]

I recently did a valve adjustment job and belt change on a u20 engine. It seemed to have fixed the problem except for the idle. The engine idled at 3000+ RPM when I first started it. I backed off the idle screws all the way, created slack in the throttle and choke cables and decreased the throttle shaft screw. The engine now idles at 2200 RPM even when warm and I've run out of adjustment points. I used carb cleaner to remove all built up grease and re-lubed the whole thing. The car idled at 1000 RPM before the valve job with the idle screws in.

Ryan
1969 Datsun 2000

[SLOroadster]

Ryan,
if your are running SUs, check your chokes and make sure they are closing all the way. Also check to make sure your needles in the dashpots are straight and not hanging up anywhere. That should help.

Will

[DatsunBucky]

Might want to check for a vacuum leak, too. I believe that can raise the idle.

[Marky510]

Check the throttle cable at the firewall end and see if it's come out of its seat. Also, check if the holders for the throttle cable are too tight, it could be crimping the housing causing a bind on the inner cable and not letting it return. Also, check that auxilary cable (cruise control cable?) for any binding. I had a similar problem on my '68 with the auxilary cable being crimped holding the throttle open slightly.

Mark