Hi, I have a '93 Toyota pickup with the 4 cylinder 22RE engine and about
110,000 miles on it. Anyway the engine is idling rough. It is almost a
rhythmic idle (speeds up slows down) in a way you could almost set your
watch to. It speeds up even worse if I turn on the A/C making it idle
faster. I took it into a Toyota dealer and they told me it was the throttle
body and it needed to be replaced. Unfortunately throttle body's run $600
new and can't be rebuilt according to several other fuel injector/carb shops
around town here. The throttle body is a disposable unit basically. I
called all the salvage yards here also and no one has a used throttlebody.
I don't even know if this is really the problem anyway. They ran a
diagnostic and cleaned the throttle body and came to this conclusion and of
course a expensive one at that. It also sounds like it might be a vacuum
leak and have tried spraying carb cleaner on all the vacuum line to see if
the engine would idle faster momentarily and nothing happened. I first
noticed this problem right after they did a rebuild back at 58,000 miles
done by Toyota under warranty. Back then it only did it when I turned on
the A/C on. Now it does it almost all the time with he A/C on or not. It
also starts to act up when I press on the brake pedal. This all screams
vacuum leak to me but I have tried everything and hell if I'm going to hand
over anymore and replace the throttle body. I have talked to several fuel
injector rebuild shops around town and had one place even look at it and
they all seems to think it is not the throttle body. I don't what to do.
The truck runs great in every way otherwise. I even felt sure enough to
take it on a long 1,000 mile trip two weeks ago. It's just when I'm sitting
at a stop light
and the guy next to me thinks I want to race him because the engine is
reving up and down like I'm doing it myself. Sorry, I realize this is a
long post I just wanted to give everyone enough information to work with.
Any help would be much appreciated!!!

Thanks in advance,

Carey

distorted_49 wrote:
Check the Throttle Position Sensor:
http://4crawler.cruiserpages.com/4x4...PS/index.shtml

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

--
Roger

I had a cyclic surge that almost drove me crazy. Happened when I had the AC
on, at idle, with the brake pedal depressed. Played with vacuum system,
found it got worse if a leak was introduced. I searched for a leak, found
none, then after I fooled with hoses going to valve on side of power
steering pump, the problem went away. So, I would look for vacuum leaks and
stuck vacuum valvves. Also, the Car Talk boys on NPR once got this question
and immediately said it was a leaking power brake booster. It could be.
But since it wasn't in my case be sure before you buy a new booster.


"distorted_49" <distorted_49@cox.net> wrote in message
news:%KjLa.172438$eJ2.80438@fed1read07...

James Andrus wrote:
If it happens w/ A/C on (or using the power steering at idle) you likely have the A/C idle up valve adjusted wrong and/or the
A/C amplifier set wrong. There is a vacuum switching valve (VSV) that is turned on w/ A/C use at idle to boost the idle speed.
There is also the A/C amp that senses engine RPM and cuts the A/C if the idle gets too low. The idle up control is the white
plastic knob on top of the intake plenum, A/C amp is behind the glove box.

--
Roger