hmmwv15

The thing is idleing really low, and adjusting the idle speed screw on the carb. does little to nothing. What's goin on?

Th3duke

Did you check your throttle body to see if it was plugged up? If so, have you adjusted the TPS?

hmmwv15

If those things aren't the problem what is? I should have went into more detail when I posted: On startup, it idles normal. When you rev it up, the idle speed decreases rapidly, so you can hardly hear it. When idleing low, it also makes a knocking sound.

hmmwv15

Ok, I dont have EFI. My engine is carbureted. I guess I misunderstood, but I have tried posting this again and everone seems to think I have EFI.

stock87

The linkages on the back are likely gummed up. There are a couple situations where it can be held off the idle screw a little bit so the screw does nothing.

Hose down the linkages with some carb cleaner and work everything by hand with the truck off and see if you can get it moving more freely.

http://www.bluebassdesign.com/boonin/carb_faq/

hmmwv15

well, the carb isn't gummed up, but I did get the thing to respond to the idle screw. It is still doing the same thing, but I adjusted the idle speed higher so that it idles high on startup, then goes to normal idle speed after it warms up. Thanks for the info by the way.

the_supernerd

There is a fast idle adjustment screw and a regular idle screw. It sounds like you are adjusting the fast idle screw.

Since your truck starting idling rough, you might also want to check the vacuum advance. Carbureted 22Rs have two diaphrams, the one closest to the distributor is pulled at idle. If it breaks and no longer holds vacuum then it will not idle like it should.