vacuum electrical problem

[85yoda]

hi to all,

Im new to this forum and have an interesting problem with my 85 toyota. First It has 320,000 miles and have been very happy with it ( got 272,000 miles out of the first engine ) but have had an interesting problem with the 3 subsequent engines. After starting and running for a few minutes the idle slowly moves up from 1200 to about 1600 rpms then, when I step on the brake it immediatly drops down to 1000 rpms and slowly revs up to 1200 then falls off to 1000 revs to 1200 and falls off to 1000 so on and so on. Now heres the kicker if I pull the brake fuse or the brake light plug up above the brake pedal-the loping stops. I have sprayed around the intake to check for leaks as well as disconnected the vaccum booster unit and conducted different vaccum tests disconnecting hoses and so forth and makes no difference (only disconnecting the electrical stops it) maybe the brain or some other sensor? Any input would be appreciated.

Thanks in advance 85yoda

[85yoda]

hi all

I think I may have gotten the answer from other previous posts and replies. with this fresh clean throttle body, plenum and intake manifold the idle speed was too high after adjusting the throttle body idle screw down the brake pulse went away. Maybe the efi computer or sensors detect too high of rpms at idle and disconnecting the brake electical bypasses the extra load? Anyway, thanks to replies to those other posts to yoda jedi. I feel slightly stupid for looking a little too hard at other than simple things.

thanks again 85 yoda

[Sidney]

http://www.geocities.com/toyotashawn/bizzareidle.html

Sidney® ™
Repairs tv's,vcr's,home/car audio out of my home
E-mail:sidneybek@yahoo.com
Dartmouth,Nova Scotia
Canada
1985 Toyota 4-Runner,solid front straight axle,factory cruise control,sunroof,22R-E,W56,RN60LV-MSEK,rusted rear step/towing chrome bumper with 244 000 KM

[85yoda]

great link thanks sidney.