high idle problems

[Drobbs 85]

Ever since I got my truck, which is an 85 K10, it seems to idle too high and take too long to come out of high idle. Whenever I start it in the morning(cold) the high idle engages but whenever I go to blip the throttle to disengage it it just wont do it. This is after I warm it up for about 5 minutes. Then even after driving it for a while, it still wont come down. Usually I get to wherever I need to go before it comes out of high idle. If I kill it after the drive and let it sit for a while and then come back, crank her up, and blip the throttle it will come down to the normal low idle. ? What gives? Also whenever it is in high idle it seems way to high, especially in park or nuetral, and whenever I put it in gear it just about snaps my head off with a hard jolt. The previous owner told me he had a new electric choke put in it,  and it does look pretty new. I sprayed everything down with some carb cleaner and that did nothing..What I wanna know is how long it should take before it will come out of high idle. Maybe this is all normal? I dont think so though..
                                                                              Thanks, Dylan

[VileZambonie]

Sounds like your choke break needs to be replaced.

[DnStClr]

Yeah, it should come out of high idle within 30 seconds or sooner or else the choke break isn't working right. It might be out of adjustment.

[Drobbs 85]

Thanks for the replies, heres a few pics of my carb..Is the choke break the small goldish round thing in the back left corner? Before I replace it, how do I go about adjusting it?

[VileZambonie]

Yes, have someone start the engine and verify the rod moves when the engine starts first. The rod should pull the lever so that it pulls you off of the fast idle cam when the choke coil opens. The choke coil is only designed to open the choke flap not drop the idle. The break drops it off of the fast idle cam and you can see this if you work the linkage. Close the choke flap and depress the throttle linkage. you will see the screw stop sit on the step on the fast idle cam. Now open the choke flap, open the accelerator and pull back on the break linkage. You should see it drop off of the step.

[Drobbs 85]

ok I messed with it a little bit and heres what its doing..The rod does move when its first started, I tried doing what you told me but I guess I kinda dont understand what you mean? Basically while its running(right?) hold the flap shut and hold the throttle but the part after that confuses me, see screw stop sit on the step on the fast idle cam? What I did do was while it was in high idle fully warmed up the choke flap was not all the way open so I opened it all the way(idle did not change) and then gave it a blip of throttle and the choke flap stayed open and it went down into low idle. After that whenever I gave it any gas it would jump right back into high idle but it would not go down to low idle if I gave it gas again(unless I held the plate open blah blah). What did I just do? Does this mean the choke break isnt working right and needs replacing?

[VileZambonie]

Are you saying the choke plate is not openeing all the way? If so that's your whole problem. Also I should have clarified. I wanted you to do this with the engine off from here "Close the choke flap and depress the throttle linkage. you will see the screw stop sit on the step on the fast idle cam. Now open the choke flap, open the accelerator and pull back on the break linkage. You should see it drop off of the step."

If you keep the choke flap propped open all the way will it stay in base idle?

[Drobbs 85]

 it does open all the way but it takes a long time, like after driving around for a while. How long should it take before it opens all the way? When its in high idle I can pry the choke flap open all the way and the idle doesnt change(stays in high idle), then while keeping it pryed open I can blip the throttle and it will go down to normal idle and the choke flap will stay all the way open like its supposed to. if I blip the throttle again it will jump right back into high idle and the choke flap will close again(not all the way closed). Also in the morning when I give it a pump the flap doesnt close all the way, it doesnt touch metal to metal..

[VileZambonie]

Take a 12V test light to ground and probe the electrical connector at the choke. Start the engine, it should light up the test light. If it does I would simply recommend replacing the choke coil and adjusting it.