It all started about 2 weeks ago, the prado started normaly and was idling at about 1500 initialy while it was cold arter traveling a couple of km i noticed that the idle had increased to about 2000 rpm. I gave it a small kick on the accelerator pedal and the rpm dropped to 1100, not the usual 750 rpm. Next set of lights same thing happened. When I had time to look at the problem I found the cruise control and the accelerator linkage had a small gap between them, by pressing on the linkage the idle returned to 750 rpm. Initialy thought it may have been the throttle position sensor TPS so again when I had time I removed the TPS, the linkage still was being held open. Turns out the throttle opening valve which is located just to the left and slightly lower than the throttle body opening has jammed and is holding the idle at the increased speed. I also checked that the vac line that operates the valve did in fact have vac present.
This valve looks to me to be a method of opening the throttle slightly when the manifold vac increases to a too high level, like when decending steep declines with the engine reving at 3000 rpm and the throttle closed.
Hope this helps somone because it also baffled my normal motor mechanic!!!!
Ken.
This valve looks to me to be a method of opening the throttle slightly when the manifold vac increases to a too high level, like when decending steep declines with the engine reving at 3000 rpm and the throttle closed.
Hope this helps somone because it also baffled my normal motor mechanic!!!!
Ken.
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