andlours

iTrader: (1)

I've noticed that my 4Runner's idle is uneven when i turn on the heat or A/C. It either raises to about 1500 RPM and stays there or it will move up and down pretty quickly between 1000 and 1300 RPM. Any help would be much appreciated. I'm pretty new to all this stuff so easy, simple instructions would be much appreciated! thanks

Fink

I don't mean to sound like a jerk but, it's perfectly normal for the RPM's to jump a bit when the A/C compressor kicks on as it is puts an extra load on the motor.

As far as the sporadic idle, can you post a video of your tach doing this so we can see it?

Fink

4Crawler

iTrader: (3)

Fast idle speed is adjustable, sounds like yours is set too high. Should be around 1000 RPM or so:
- http://www.4crawler.com/4x4/CheapTri...ne_Pix/13.html

If too high, you'll have an unstable idle speed as you hit the ECU fuel cut point, especially if you hit the brakes:
- http://www.4crawler.com/4x4/TLCA_Tru...ech.04.09.html

andlours

iTrader: (1)

Here's a video of it happening. Also, when i turn on the A/C I get a belt squeaking sound. It stops immediately after I turn off the A/C. It doesn't do it every time, but when it does, it's only when the A/C is on. Any help would be appreciated!

Here's the link:
http://www.youtube.com/watch?v=fiY-cL7-0bQ

Fink

The squeaking is most likely the belt - easy fix.

Thanks for the video! I would follow 4Crawler's advice.

Fink

Squeebs

my 3.0 idled at 1200 with AC on.

my 22re idles at 600ish with ac on.


i think its a yota thing.

4Crawler

iTrader: (3)

It means the the 3.0 is set a little too high on the fast idle screw. The 22RE is either set too low or the vacuum line or port to the idle up VSV and valve is clogged (very common) or the A/C amplifier RPM setting is set incorrectly and is not switching on the fast idle VSV.

andlours

iTrader: (1)

Like I said before, I'm really new with all of this stuff. Would one of you be kind enough to help walk me through how to fix both the belt and the idle?

4Crawler

iTrader: (3)

Belt: Loosen center nut on idler pulley, turn adjuster bolt to tighten the belt, then tighten the center nut to lock it in place.

Idle: Turn the white plastic knob on the idle up valve to lower the idle speed when the A/C is on. See my link above.

andlours

iTrader: (1)

Well, I adjusted the idler nut and the idle issue is solved. I'm still not sure about the belt though, cuz it only squeaks sporadically, usually only when it's cold. Could anyone give me further advice on this issue?
Thanks

4Crawler

iTrader: (3)

Could be a number of things.

1. Belt too loose - fix is to tighten the belt. Should be about 1/2" deflection or so in the belt when you press hard with your thumb in the longest section between pulleys.

2. Belt glazed or worn out. - fix replace belt. One thing you might try is to apply some "belt dressing" to the running belt and see if that helps. A good hardware store should carry it, liquid that softens up the rubber and makes it a little tackier so it does not slip.

3. Idler pulley bearing could be dried out or worn out - fix is to replace the bearing. Way to check, remove belt and spin the idler pulley and check for extreme looseness or tightness or a gritty feeling when you spin it. If found, remove pulley, pop out bearing, clean and re-grease or replace as needed.

bob200587

I know that with mine it jumps up and down if the air conditioning system is low on refrigerant because the compressor is kicking on and off.

Fink

Roger Brown (4Crawler) FTW!



Fink

angrybob

Hmmm...my ac vsv did not pass the FSM check for flow so I replaced it. I also jumper vacuum to the AC idle up valve and it works, adjusts, etc. With the new vsv it still does not increase the idle when the AC is turned on. Vacuum port from intake to AC idle up valve flows. Oh, new vsv came with new vacuum lines.

Really not a big deal because the AC season is over, but I do want to fix this.

Next steps? I'll be away from my 4runner until Sunday so I am just trying to line up some repair options.

4Crawler

iTrader: (3)

Likely the A/C amplifier under the dash (behind the glove box) RPM setting is too high and not allowing the VSV to be switched on to boost the idle. Basically the A/C amp has a minimum RPM below which A/C is cut off to avoid bogging down the engine. So that RPM should be set a little below the normal idle RPM. Then the idle up valve RPM should be set a little above the normal idle RPM w/ A/C running. This way, when you switch on A/C, the amp sees the RPM is above the low cut point so flips on the VSV. Then that boosts the RPM up a bit to keep above that low RPM cutout point and all works as designed.

Or it could be the signal from the A/C amp is not activating the VSV, put a test light on that plug and see if it lights up and also try powering up the VSV and see if it opens. Should also be able to put a finger in the VSV and feel for the click as it gets power applied to it.

93Xtra-Cab

That happened to my truck while I was recharging the AC. It turned out that the entire compressor seized up. The uneven idle was from the belt slipping and then catching on the stuck AC pulley. That's also what the squealing was from. I hope that's not the case for you because replacing the compressor is a PITA, at least for me because I have the 3VZ-E

angrybob

I think I'm going to check the signal to the VSV first and
I recall that it did click when I installed the new part, but I'll check again.

HISTORY
I set the A/C amp knob just below my idle of 900rpm after the A/C clutch did not engage at idle (found that on your site btw - thanks).

That led me to the next step - now that the A/C clutch was engaged at idle, it dropped 300rpm without a correction. I turned the white screw all the way in and out with no affect.

Next, I check the VSV per the FSM and it failed the air flow test. I replaced it and the idle still did not rise with the A/C on. That is the current status. I did check the flow of the vacuum line that runs from the intake manifold by the idle speed adj. screw to the A/C idle up valve. It checked out OK too.

4Crawler

iTrader: (3)

The VSV is basically like a relay for vacuum. When energized, it just passes the input vacuum to the output line. Then when off, it vents that output line to atmosphere through the little round cap and filter. See if it is getting power and if so, is it switching the vacuum signal from input to output.

angrybob

Never did get this resolved...weather got cooler

Now that the heat is coming, I dove into it today and the VSV and its signal check out fine, and A/C amp trim pot is set to below idle

If I jumper another vacuum line to the VSV it work perfectly, bumps up RPM, and is adjustable.

Next step was to pin out the harness per the FSM to see if the A/C amp is good. If the harness checks out per the FSM specs, the harness is good and replace the A/C amp. I wish it was that easy.

It appears that I have the main harness ground that is FUBAR. All tests are with IG 'ON', a/c at MAX Cool, and fan on high. The first step is to check pin #7 (the middle pin in the connector) to ground for continuity - NOPE. This measurement's purpose is to confirm a good ground if there is continuity. Of course, all of the following pin measurements to check for battery voltage were off too because the ground is pin #7.

Oddly I have continuity btwn pin #7 and ground with the IG 'OFF'.

I would like to get this resolved for the sake that something is not right, but its not a big deal. My A/C compressor works at idle and the air is ice cold. Its a weekend toy and I can 'right foot' idle up if I have to on the trail.