1991 Toyota 4Runner 22RE.

With the truck in N or Park the Idle sits at about 800 to 900 rpm range
with the Truck in drive its around 600-700 rpm's

Turn the rear heater on. No idle up (This is fine)

Turn the front heater on Drive it Idles up to about 800 rpm
Turn the front heater on in Park or N and it idles up to 1200 - 1500 RPM ????

This is even after the truck has warmed up.

With winter comming soon. I usally start the truck up and let it warm up in the driveway a bit. But having it Idling in the driveway at 1500 rpm is CRAZY.

Whats the Fix guy (& Gals)

 

BUMP.

Its getting cold here and Canada Eh !

AT least tonight it was.

 

does you runner have a/c, if so when you have it in defrost or floor/defrost, it will run the a/c compressor to help dehumidify the air and help defog the windows faster, that may be just the a/c idle up. now if you don't have a/c.....

 

I do have A/C but not using it right now.


What Im wondering Is how do you adjust the Idle Up for the heater ? or is the adjustment for A/C idle up the same as heater idle up ?

How do you adjust the idle up I guess will be the next question.

 

Plastic knob atop the idle up valve on the intake plemum is where you adjust it (see white hex-shaped knob in the image below). Note that often, if you are running the defrosters, the A/C will automatically come on to dry the air for better defrosting. On my '85 you have to turn on the A/C manually, but I think later vehicles did this automatically.