Hello everyone.....I need some help with a few questions.First is my air conditioning in my 1989 Toyata truck.My problem is that my a/c works fine as long as I am going down the road,but as soon as I come to a stop the compressor kicks out.You can hear the relay kicking on and off during these conditions.I have adjusted the relay behind my glove box to no avail.I then procedded to try and increase my idle this also did not work.Now I have 2 problems...An a/c that works as long as the idle is up and now my idle screw works itself out of adjustment every week or so to the point it stops running as soon as I get off the gas.I have temporarily fixed this with electrical tape but need a permanent fix.I would appreciate any feedback...
Lastly would like to know everyones input on replacing my 02 sensor.I have 221k miles on my truck and have never replaced this sensor.I am currently getting 20-21 mpg.Would you do the preventive maintenance or wait till it starts acting up.My sensor is before my cat so would this be called an upstream sensor?Thanks for any help....Brownie

 

Adjust the A/C idle up valve, not the idle screw on the throttle body:
http://www.4crawler.com/4x4/CheapTri...ne_Pix/11.html



O2 sensor can be tested, observe ~8 0.2-0.8 volt swings in 10 seconds w/ engine running 2500 RPM. Or check for stored codes in the ECU to see if any are present and related to the sensor.

 

Thanks for the feedback 4Crawler.I grabbed my flashlight and went outside to give this a shot.I ran the a/c idle valve in slowly and nothing changed.I then ran it all the way back out an no change either....Any other suggestions besides a garage.Thanks again for your help.

 

Check the idle up valve and it's associated Vacuum Switching Valve for clogs. It is not uncommon for the small vacuum lines and fittings to get clogged with crud from the intake. If that is OK, you can bypass the VSV by running the intake vacuum line directly to the idle up valve. If the idle speed increases, that points to an issue with the VSV. It make be internally clogged or it's coil may be burned out.

 

how about the same deal except 3vze?