High Idle is pi$$ing me off

[cshogo]

I have an 89 Lude 2.0 carb I can't keep the idle below 2000-2200 RPMs. Whether the car is hot or cold. I have found alot of threads regarding this problem and the majority of them end with open vacuum lines. I replaced about 100 vacuum lines and the problem still exists (About 25 to be exact). What can I check or replace on the Carb that would resolve this problem. I'm able to force the idle down by pushing down on the whole assembly but as soon as I press the gas pedal, the problem comes right back. I drenched my carb and all the surrounding areas with Carb Cleaner and still having the problem. How do I replace the choke or what else could be causing that problem. Thanks..

[x3r0]

I don't think the choke will matter, have you even thought of checking the adjustments? First thing to do is adjust the throttle idle screw, passenger side of carb. Its a phillips head. Turn it a lot, cause its a long screw :-) but u can actauly see how it works, it contacts a metal part to pull back the throttle.
If that doesn't work, maybe whatever causes your car to idle on cold is always idling your car high and that could also be a problem, but I am unsure of what controls that on your car. Another problem that would cause this is a bad alternator, u may see the alternator light randomly on.

[A20A1]

It might be the throttle return spring... you may need to replace the spring which I doubt they make the part for... or you can fin a place to hook up an auxillury return spring... also check the tension on your throttle cable... it's better to have it a little loose so the return spring doesn't have to work as hard to close the throttle.

Also spray the trottle shaft and linkages real good with WD-40... but if they are really dirty clean them off with carb cleaner then spray WD-40.

[x3r0]

hmm, what and where is the sensor that actualy initiates the cold fast idle?? Ive been wondering this.

[geofstan]

if you have tried adjusting the throttle screws and it is still fast revving try loosening the throttle cable (let car warm up first) , if cable isn't adjusted correctly it can prevent the throttle cam from closing .

[locknload68]

hmm, what and where is the sensor that actualy initiates the cold fast idle?? Ive been wondering this.

Thermovalve A controls the vacuum to the fast idle components depending on coolant temp.

[Blkblurr]

Check the thermo valve that controls the high idle kick down. This returns your idle to 750 rpm after it gets set when your engine is cold. Sometimes this thermo valve fails, sometimes the vacuum diaphram in the high idle kickdown has a leak in it and sometimes the high idle kickdown mechanism gets stuck and needs to be inspected and cleaned or replaced. This is fairly common on older carb engines.

[cshogo]

Well the alternator light isn't on and I think the next thing to check is the thermo Valve. Can someone tell me where that is located. Furthermore, it may be a coolant temp sensor. Could anyone tell me if the temp sensor is bad, will that cause the problem. The temp gauge is displaying correctly so I wasn't thinking of that. Question is if the temp sensor is bad, will the inside temp gauge still work?

[geofstan]

The thermovalve is located on the back of the engine on the drivers side with hoses 17,18 & 19 leading to it.

[soljaboy2000]

Check the thermo valve that controls the high idle kick down. This returns your idle to 750 rpm after it gets set when your engine is cold. Sometimes this thermo valve fails, sometimes the vacuum diaphram in the high idle kickdown has a leak in it and sometimes the high idle kickdown mechanism gets stuck and needs to be inspected and cleaned or replaced. This is fairly common on older carb engines.

Where is the vacuum diaphram and kick mechanism located?

[geofstan]

vacuum diaphram is located inside the choke opener

[Blkblurr]

The best thing to do is get a Helms service manual or look at the online manual for info on locating anything on the car. If you look into the fuel section for carb engines, it will give you all the info you need to locate and repair problems you are having. There is a thread here somewhere that directs you to an online manual.

[A20A1]

Actually you guys, he has a different carb setup then we do... although some things are simmilar.

You do have the dual keihins right?