1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

3VZE high idle?

Discussion in '95-older Toyota Truck Tech' started by e rock, Aug 15, 2005.

  1. e rock

    e rock

    Messages:
    1,612
    Likes Received:
    9
    Joined:
    Feb 24, 2004
    Location:
    Monroe, WA
    A buddy of mine has a 95(?) 4Runner with the 3.slow that won't idle below about 1200 rpm, and usually in the 1500 - 1900 range. It's been going on for a few months now, but it wasn't really an issue except now he needs to get it smogged.

    Some of the details are sketchy, but he says that it started doing this after he sprayed some carb cleaner into the throttle body to clean it out (I don't know why...). The stealership wanted to charge him $700 to replace the throttle body assembly since they thought something was sticking and they would not just clean it up. Their assumption was that the carb cleaner knocked something loose and clogged up something.

    I pulled the TB off over the weekend. I cleaned, polished, blew out, etc. I'm not any kind of expert, but the whole assembly seems exceedingly simple. I cannot see how it could possibly be causing the problem unless it's a vacuum leak but the whole thing seems tight.

    I removed the throttle return damper thingy with no result. I backed off the low throttle limit screw and if I manually rotated the throttle valve to the point that the butterfly was physically touching the walls of the TB, the idle would drop to about 1000 - still not the 800 it's supposed to be.

    If I applied a LOT of suction to the EGR valve, the idle would drop to about 800, but it was running horribly by that point.

    I can get a new TB from CDan for about $350 IIRC, but I just don't see that as the problem??

    Any ideas? Maybe it's a common problem?

    Eric
     
  2. e rock

    e rock

    Messages:
    1,612
    Likes Received:
    9
    Joined:
    Feb 24, 2004
    Location:
    Monroe, WA
    -=Replying to myself purely for future searchers=-

    The throttle position sensor (TPS) wasn't working properly. All of the contact traces were working fine and were within resistance spec at the various operating angles except the idle circuit. I pulled it off the TB, opened it up (not really supposed to, but we had nothing to lose) and cleaned the circuit board and contact arm.

    Put it all back together and verified that the idle circuit was closed when the butterfly was at the throttle stop screw. Adjusted per spec and it works great now and passed emissions. If it ever goes out again, we'll just order a new one from Dan ($70 IIRC), but cleaning it did work in a pinch.