89whitetoyota

It is still cold here so the truck will idle high, then idle down to normal idle as normal. As soon as i use the gas pedal it goes back up to high idle, however I can pop the gas real quick and it will go back to normal idle. This happens cold, and at operating temp.

So, for example. I can drive the truck 25 miles, and when i get to the exit and compress the clutch pedal it will go to high idle, i then pop the gas pedal real quick and it goes down to normal idle. Is this a sticking throttle cable or are the adjustment nuts for the throttle body messed up?

Thanks
-John

myyota

A throttle cable can go bad and start to fray and come a part, best thing to do is remove the throttle body and clean it, put it back on and see if that helps or fixes the problem, if not then its probably the throttle cable.

Andrew Parker

This component is intended to slow down the rate at which the throttle plate and TPS go back to the fully closed idle position when you let off the gas pedal. If the diaphragm inside has lost its compliance it can influence your actual idle position as it could keep the shaft from rotating to the hard stop.

ev13wt

If the throttle cable fray enough where it enters the sleeve, it will first do your issue, then if it frays more it can simply get stuck in the "open throttle" position. If that happens, please remember to quickly turn off the ignition.

Toyota and their throttles, pfff, should have taken into account we drive these things for "ever"






If you remove it or adjust it way down, you get lovely backfire popping on deceleration. Gonna want it there for smog though.

.

scope103

All of these could be the problem, and it isn't too hard to tell which. At the point where you think it's idling high, pop the hood and push the throttle plate closed with your finger. You shouldn't be able to move it; if you can, then SOMETHING is preventing the throttle spring from pulling the plate closed.

Andrew Parker

When I had discovered the rubber grommet had split in half at the accelerator pedal and that no matter how much I depressed the pedal the throttle plate would never get to WOT, I decided to take out the slop in the cable after I had repaired the grommet. When you adjust the outer housings effective length by running the pair of nuts along the threaded end you can remove the cable slack and assure the pedal will give the throttle plate a very complete horizontal attitude when at WOT. However, should one take on this adjustment it is advised that it be done when the under bonnet temperature is at a "normal" operating temperature and not when everything is dead cold. The reason is because the plenum and the cable are in close proximity to one another and it warms up the cable for a very good length and this causes the thermal expansion of the outer housing to increase its effective length. I had set my cable slack when it was cold and when it was all warmed up the cable would not let the throttle return to the hard stop and my idle was well above 1000 RPM. I should think the FSM has a specification for setting the cable slop!
ATGP