Idling too high after carb rebuild. Need advice

Discussion in 'Maintenance/Repair' started by raylcc, Aug 31, 2013.

  1. raylcc

    raylcc Addict

    Joined:
    Feb 28, 2012
    Messages:
    569
    Likes Received:
    3
    Location:
    Denver, CO
    Truck:
    89 Regular Cab. The weirdo with the stock suspension.
    I rebuilt the carb (22r) because it failed emissions. The good news is it passed emissions now. The bad news is that it now wants to idle between 2000 and 2500 rpm. (guessing as I don't have a tach, but its way higher than it should be.) It idles high enough that on a flat surface, I don't need to press the gas pedal to take off, just let out the clutch and it goes and while driving along, I have a scary form of cruise control as the truck just accellerates without the gas pedal being pushed. If I let off the gas and push in the clutch, the engine actually increases rpm's instead of dropping.
    Now heres the odd part: If at a stop, I rev the engine up to almost redline, the engine rpm's will drop down to a normal idle. the idle then is actually too low as it stumbles to keep running. This will last until I take off or press the gas again and it resumes its high idle until I over-rev it again.
    I'm a little stumped, so any advice would be appreciated.
    Thanks.
     
  2. Xs5875

    Xs5875 Addict

    Joined:
    Nov 18, 2012
    Messages:
    989
    Likes Received:
    9
    Location:
    Greenville, Ga
    Truck:
    1994 Standard cab 22re 5 spd
    Sticky linkage?
     
  3. raylcc

    raylcc Addict

    Joined:
    Feb 28, 2012
    Messages:
    569
    Likes Received:
    3
    Location:
    Denver, CO
    Truck:
    89 Regular Cab. The weirdo with the stock suspension.
    Sounds reasonable? How would that be fixed? should I spray the linkage with wd40 to test it?
     
  4. scrub88

    scrub88 Toyotaholic

    Joined:
    Apr 14, 2007
    Messages:
    1,685
    Likes Received:
    10
    Location:
    tn memphis
    Truck:
    88 toy short bed
    If u wanna test your linkage while the trucks idling rotate your throttle cable bracket the opposite direction it would normally go .. When pushing the gas pedal ....if the idle drops down and settles t a normal rpm it may be sticking .. Are not fully closing .. But there are other areas that will also raise idle on carbs but try that first
     
  5. Xs5875

    Xs5875 Addict

    Joined:
    Nov 18, 2012
    Messages:
    989
    Likes Received:
    9
    Location:
    Greenville, Ga
    Truck:
    1994 Standard cab 22re 5 spd
    Lots of times while you are rebuilding you go to town spraying carb cleaner..the gunk that washes away sometimes collects where it shouldn't and prevents normal movement of things. It prevented my IAC from closing on my tacoma and the idle wouldn't go below 1500.

    With truck off, manually close the throttle with the breather off so you can look inside the carb. Have someone slowly press the gas pedal in the cab fully then let it off slowly.

    Compare the differences...it it stops short of closing, then there ya go.
     
  6. raylcc

    raylcc Addict

    Joined:
    Feb 28, 2012
    Messages:
    569
    Likes Received:
    3
    Location:
    Denver, CO
    Truck:
    89 Regular Cab. The weirdo with the stock suspension.
    Ok, this one was weird. The bracket for the throttle linkage is a kind of "c-shaped" bracket thing at the back of the engine and has a half-moon pulley where the throttle cable attaches. Pressing the gas pedal pulls the cable, which rotates the pulley and turns the the throttle on the carb. (to massively oversimplify, but you get the idea.) This "C-shaped" bracket is held onto the engine with two screws and a "centering tab" that is bent into the bracket. You can see its obvious that the bracket is meant to fit the tab into the slot and be bolted down.
    However:
    Mine has spacers under the bracket to lift it up. And by spacers, I mean, metal washers. We had put them back as three on the bolt closest to the pulley and two on the other. I thought this must be a mistake, so I took them off which made the problem of over-reving idle worse. So I tried to put them back, and lost one.
    Down somewhere in the bowels of the engine bay, stolen by Toyota Gremlins, not sure, but I decided to just use two on each bolt to make the bracket even and test it.
    To my surprise... It fixed the problem! Truck runs nice now. Idles a little low, but I just have to adjust it.
    The washers raise it up high enough that the tab no longer fits into its hole to center the bracket.
    Does anyone else have these washers under your throttle bracket?
    I thought everything was stock on my engine, so I was wondering if this was a fix for a design flaw from the factory of if some amateur mechanic added them to get 15 extra horsepower on the butt-dyno. :confused:
    Thanks for the help either way. it gave me a place to start looking.
     

Share This Page