Idle speed 2.1 DJ

[TamarandJulian]

My 87 2.1 DJ is idling too fast and even with the idle screw fully tightened the engine is running at about 1500-2000 RPM. The mixture is good and running fine otherwise. Should I suspect:
worn throttle body?
idle control valve?
ECU?
temperature sensor?
Any guidance on this much appreciated.
Cheers
Julian

[kevtherev]

Air leak?

[jed the spread]

My 87 2.1 DJ is idling too fast and even with the idle screw fully tightened the engine is running at about 1500-2000 RPM. The mixture is good and running fine otherwise. Should I suspect:
worn throttle body?
idle control valve?
ECU?
temperature sensor?
Any guidance on this much appreciated.
Cheers
Julian

Make sure the arm is returning fully back on the throttle. Mine did this because the spring lost some of its spring. I poped a cable tie over a couple of the coils to shorten it as a quick fix and it works fine now.

jed

[sonic23]

First thing I'd check is if the throttle body switch is shutting off at idle. If it's not - then the ECU will not get the correct signal and will cause the engine to over-rev at idle. With a bit of luck, you should just have to adjust the switch

Lots on this thread:
https://club8090.co.uk/forum/viewtopic.p ... h#p7442631" onclick="window.open(this.href);return false;

Rich

[Simon Baxter]

Air leak, vac advance can leaking, servo pipe, connection between throttle body and plenumb.
Idle switch (as noted) idle air control valve leaking (most probably, try disconnecting when warm or clamping hose when warm)