22RE T100 Idle is HIGH, LOW when pressing brakes

22RE Fuel Injected, 1992, 4x4

My idle races from high to low, high to low whenever I press on my brakes (from 900 rpms - 1800). Crazy huh!

The truck runs great when your driving it on the freeway or just starting it up. I checked the EGR, PCV valve, TPS sensor, cleaned out the throttle body and intake manifold. I also checked the vaccume system for leaks, even hand cleaned the fuel injectors, & new plugs. To no avail.


I see other people posting similar issues - but the truck eveuntaly idles great! It did not start doing this until I cleaned the intake manifold and throttle body.

My 1992, 22RE as it sits right now...
See anything obviously wrong that I dont?

ENGINE IMAGE 1 -600kb
http://www.geocities.com/cold_phoenix/t100/22re_01.jpg

ENGINE IMAGE 2 -600kb
http://www.geocities.com/cold_phoenix/t100/22re_02.jpg

ENGINE IMAGE 3 -600kb
http://www.geocities.com/cold_phoenix/t100/22re_03.jpg


Bouncing Tach Video (Windows Media 9)
you can hear how bad it sounds too
the files are zipped because the web host does not like windows media being posted
Problems downloading: if you get an error, immediately click on your browsers REFRESH button and you should then get the option to download the video! :D

STARTING ENGINE VIDEO (COLD) -2MB
(in this video I start the truck never giving it gas, I am not touching any pedals and the idle is climbing higher and higher? Normal?).
http://www.geocities.com/cold_phoenix/t100/c.zip

ENGINE BEGINNING TO WARM UP -2MB
(TACH BEGINS TO BOUNCE, Eveuntally stopping until break pedal is depressed)
http://www.geocities.com/cold_phoenix/t100/w.zip

The screw on the front of the throttle body needs to be turned counter-clockwise (I must have nudged it wrong), until the engine rev's down. I held the brakes down with a sub-woofer and slowly turned this vaccume screw. What purpose does it have - I dont know I think it effects overall vaccume pressure - thats why the brakes were slugging the system down (there vaccume demanding). This threw off the ECU.

Now I turned this large screw until I was idling down around 1000 rpms. and the rpm bobbing stopped.


YAY!

hi yes we are having same issue, so far what we have discovered is that if we remove the fuse for the stop light out of the fuse panel the issue goes away, so is this still a vac issue with the booster or not, we will try adjusting the throttle and see what happens.

I did a test where with the fuse in it was cycling up and down, then i removed the fuse and pressed the brakes nothing idled at 1100 rpm perfectly, then put he fuse back in and pressed the brakes, cycled from 1100 to 1800 back and forth, im so confused where do i begin. :headbang: