Everytime i stop at a redlight my truck idles up and down but soon as i take my foot off the brake without acclerating it idles normally. when i put the brake on again it starts idleing up and down again. anybody else expereince this?

 

sounds like a vac leak, maybe on your brake booster

 

i'll check thanks

 

Assuming this is a 22RE engine: Sounds like the classic "idle too high/fuel cut problem"; the solution(if that's what it is) is to lower the idle speed setting to factory value. Explanation: The EFI system cuts fuel flow when the brake pedal is pressed; at regular idle this makes no difference, but if it's idling too fast, part of the fuel flow is under the governance of the EFI system; this is the part that gets 'cut away' when you step on the brake.

 

or check the idle-up valve connections, and make sure the solenoid for the ac/idle-up isn't sticking. mine quit working, so I just re-routed the vaccum lines so that the motor thinks I have the AC on all the time that way it doesn't bog down at idle with the AC on, but it does the same thing you describe at idle. It's pretty annoying; I'm thinking about undoing the setup since it's getting a little chilly again here in Fl this time of the year and I wont be using the AC...

 

I know this is an ole thread, but how did you re route the vacuum lines to do that?? could you please provide pics. Mine is doing the same thing and toyota wants 140 plus for the idle solenoid switch.

 

nickxrunner what year and engine do you have?

 

I have a 22re in 92 xcab with a 5 speed.

 

I have a '94 with 22re and I had the same problem. Mine ended up being the Idle Air Control Valve. It is directly under the throttle body and it has two coolant hose going to it. Its purpose is to let some air go around the throttle plate until the engine warms up. As the coolant warms up it closes the valve and stops letting air go by the throttle plate. If the IACV gets clogged, as mine was, the valve never "knows" when the engine is warmed up and therefore never closes letting too much air get by AFTER the engine warms up which in turn raises the idle and then the engine gets caught in the loping idle loop. It happens when you brake because the computer cuts the injectors off when you brake until the idle gets too low the cuts them back on until the idle gets too high (because of too much air)........an so on.

Assuming that your setup is similar to mine (I'm not totally sure that it is) check the valve by taking the intake off the throttle body and there should be a small hole just in front of the throttle plate. Put a piece of duct tape or some other tape that will not come up easily over the hole. I would make sure you cover well around the hole. Then put the intake back on and start the truck. Let the engine warm up and then go for a drive and see if the problem is "fixed". You may notice that until the engine warms up you might have to "help" it idle. Also, on mine until I tried this test I could turn the idle adjustment screw all the way down and the engine would still run and idle high, the engine is suppose to cut off. If you do the "tape test" and it appears to fix the problem you will need to change the IACV. I have heard of some people simply cleaning it out and changing the gasket but I replaced mine. I hope this helps...good luck.