Topic: BAD IDLE

[PARTSDEV]

hey guys-thought i would run this by you all.1995 22re 4x4 pickup that i just got.cant give alot of insight on the upkeep of the vehicle because i just got it.problem is when-and only when-i hit the a/c button the idle goes up end down-almost stalling out.this is most-or only noticable when at a stop.no problem when botton is turned off.idle continuosly goes up and down when the button is pressed.???i was hoping there was a solenoid that kicker the idle up when the ac is on but dont know-that all may go through the pcm? thanks for any help.

[gtoyonrocks]

I would recommend cleaning the throttle body. I have never experienced this problem but I'm sure there is someone here that has.

[PARTSDEV [OP]]

did some more reserch last night-it only happens when the brake pedal is depressed.i searched these forums for hours yesterday and i know i saw a reply to someone with close to the same problem that had to do with the base idle setting and the pcm trying to adjust for a wrong idle rpm setting.THANKS FOR ALL REPLIES ILL KEEP SEARCHING.

[gtoyonrocks]

Good luck man... I don't ever mess with the factory setting on mine but if they have been messed with in the past then I will set them back to the factory settings.

[PARTSDEV [OP]]

WOW-did some more searches-clould be a lot of different things.im thinking a quality shop is the best way to go.

[Snowtoy]

If the idle surges when you have the foot on the brakes it is usually a sign of a vacuum leak.

The engine idle itself could be set wrong, and when you have the a/c on it is causing the ecu to try and correct the idle speed and the readings from the TPS(throttle position sensor).

There is an idle-up control unit behind the glove box dash that could be bad. 
Since the ruck is new to you, I would inspect/replace any of the vacuum lines that are cracked/brittle, then check the idle a normal operating temp, and adjust to about 750-800.  If the problem still persists there is an "Idle-up" control unit behind the glove box that is adjustable.  You can do all of this at home and save yourself a good bit of money since these are likely the first thing a shop is going to do.

I can' remember if this '93 Toyota Truck FSM has a troubleshooting section in it or not, but it is worth a look.  While it is for the '93 model year it will work for basically all 22re's.

[2manytoys]

The brake booster can be a huge vacuum leak. Unplug the hose to it and plug the port on the intake and see if the problem goes away.

[gtoyonrocks]

That's some good insight. I would definately recommend looking into it yourself unless money is not an issue for you.

[PARTSDEV [OP]]

OK-checked the idle setting-right at 750to800.didnt know what to do next,but thinking it might be vacume related i looked over all the lines to be sure there is  no leaks im thinking i need to do all of them.but since i had someone over to help me we decided i would sit in the truck-a/c button on,foot on the brake pedal,idle loping,we turned "the vacume thing with the spring/screw adjuster" to see what would happen.1 and  3/4 turns in=no more problem! now i just bought a cheapy manual and cant find the vac/adj thing in there anywhere.-HOPE IT WONT SCREW ANYTHING UP.

[whokrz]

That screw is made to adjust the idle with the ac on so it won't cause any problems. If the screw is out to far it will increase the idle. When you hit the brake the computer sees that the idle is to high and cuts it. In my signature is a link to factory service manuals that you might find useful in the future.

[PARTSDEV [OP]]

thanks whokrz-