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Thu May 03, 2012 5:04 pm

Any reason not to try to correct a little higher than normal idle with the Big-ass slotted screw on the
throtle body? The pro-traning manual calls it basic engine adjustment?

Thu May 03, 2012 5:14 pm

Timwhy wrote: Any reason not to try to correct a little higher than normal idle with the Big-ass slotted screw on the
throtle body? The pro-traning manual calls it basic engine adjustment?

More than likely your high idle is caused by a vacuum leak, check everything very carefully before messing with the AFM.

Thu May 03, 2012 9:21 pm

I plugged all my air leaks, and I can screw my BIG ASS idle screw in and the van will idle at a normal idle, with it out at all it idles around 1K, stupid worn throttle body...

Fri May 04, 2012 8:30 am

You can check the throttle stop screw too it may be holding the thro ttle open a little.

Fri May 04, 2012 10:47 am

Wildthings wrote: Timwhy wrote: Any reason not to try to correct a little higher than normal idle with the Big-ass slotted screw on the
throtle body? The pro-traning manual calls it basic engine adjustment?

More than likely your high idle is caused by a vacuum leak, check everything very carefully before messing with the AFM.

My high idle is around 1000-1100 rpm's. I don't believe that I have any vacuum leak as I
have given everything the "Twice over", new intake boots as well as newish vacuum lines.

What will it hurt to move the screw to lower the idle alittle? As far as the AFM I have not opened
that up as the PT-manual suggests for a rich running van.

Fri May 04, 2012 1:12 pm

Timwhy wrote:
What will it hurt to move the screw to lower the idle alittle?

Don't think I have ever touched that screw. Always been under the impression that if someone else hasn't messed with it then it should stay in adjustment. Of course someone may have actually messed with it or you may have sufficient wear that it would require adjustment.

Is your throttle cable allowing a full return to base idle?

First before you mess with that screw, I would recommend removing each and every hose from the plenum and throttle body one by one and plugging their ports to see if that makes any difference.

Fri May 04, 2012 1:18 pm

Wildthings wrote:
Don't think I have ever touched that screw. Always been under the impression that if someone else hasn't messed with it then it should stay in adjustment. Of course someone may have actually messed with it or you may have sufficient wear that it would require adjustment.

Is your throttle cable allowing a full return to base idle?

First before you mess with that screw, I would recommend removing each and every hose from the plenum and throttle body one by one and plugging their ports to see if that makes any difference.

Thank you for the reply! Newer Plenum and newer intake tubes, new intake boots, new gaskets
and new clamps on boots.

I have had the van for over three years and the idle has always been on the high side of 1000rpms.
Everything seems to be working according to plan accept the idle. TPS works as it should according
to the PT manual.

Maybe some one did mess with screw before I got it?

Fri May 04, 2012 1:27 pm

Timwhy wrote: Maybe some one did mess with screw before I got it?

Certainly a possibility, maybe it's time to get the manual out and see how it is supposed to be adjusted.

Fri May 04, 2012 1:35 pm

24.51 of Bently:

"check idle speed rpm, correct if necessary using adjustment screw (1)"
(points to large screw on AFM)

That's where I have always adjusted the idle if EVERYTHING else is working correctly.

Fri May 04, 2012 1:38 pm

Live a little. Turn it in a 1/4 turn. If the apocalypse happens, we will know why.
After you adjust, wait a minute or so for the effect.

Fri May 04, 2012 1:48 pm

wareiter wrote: Live a little. Turn it in a 1/4 turn. If the apocalypse happens, we will know why.
After you adjust, wait a minute or so for the effect.
Make sure you know where you're turning *from*. I've tweaked my idle screw and CO mix screw (while trying to get my CO in line with what Bentley says) sufficiently that I need to keep the RPMs over 1500 for about 30-45 seconds on a cold start for the engine to keep cranking. Getting that fixed next weekend. :| Only noticed this the day after I had gotten done adjusting the mix, when the engine had cooled completely.

If I'd known what my starting point in adjusting was, that wouldn't have been a problem. Live and learn.

Sat May 05, 2012 6:29 pm

All it does is let more or less air go around the completely closed throttle butterfly, depending on if you tighten or loosen it...

Sun May 06, 2012 12:10 pm

I would turn it all the way in and count the revolutions, so you know where it was set, then adjust it. If it goes all the way in and the idle is still too high, something else is wrong.

I believe you are supposed to disconnnect the idle stablizer connector, then adjust the warm idle to 750-800 with that screw. Then when you plug in the idle stablizer the idle should rise a little bit. My idle is nice with the idle stabilizer unplugged and I have about 1.5 turns left. But the idle jumps way up when the valve is plugged in and the screw has to be turned all the way in. At that it still idles around 1250 and surges/hunts +/- 200 rpm. I am guessing that means the valve is good but the idle computer is not. In the warm weather it doesn't seem to be a problem for me to leave that unplugged.

Sun May 06, 2012 2:23 pm

davevickery wrote: I would turn it all the way in and count the revolutions, so you know where it was set, then adjust it. If it goes all the way in and the idle is still too high, something else is wrong.

I believe you are supposed to disconnnect the idle stablizer connector, then adjust the warm idle to 750-800 with that screw. Then when you plug in the idle stablizer the idle should rise a little bit. My idle is nice with the idle stabilizer unplugged and I have about 1.5 turns left. But the idle jumps way up when the valve is plugged in and the screw has to be turned all the way in. At that it still idles around 1250 and surges/hunts +/- 200 rpm. I am guessing that means the valve is good but the idle computer is not. In the warm weather it doesn't seem to be a problem for me to leave that unplugged.
incorrect. tencentlife correct me on this just a few weeks ago. :) The Idle Stablizer stays plugged in, what you want to disconnect is a green wire at the forward left of the engine compartment - it's the hall sender signal that goes to the idle stabilizer circuit. The idle screw and CO mix should be adjusted with that wire disconnected, and the ICSV will behave statically rather than dynamic.

Sun May 06, 2012 2:30 pm

I've got an idle problem now too. Geeezzz. How do you get to the idlle control black box behind the right tail light? There's ducting in the way and I can't see crap. 2.1 WBX

Sun May 06, 2012 4:54 pm

Rodknock wrote: I've got an idle problem now too. Geeezzz. How do you get to the idlle control black box behind the right tail light? There's ducting in the way and I can't see crap. 2.1 WBX

Remove the right tail light, then reach in above the ducting (you have to have a little trust here), and you will feel the relay. Wiggle it up and the harness and relay will come off of their mount. Pull it toward you and slide it under the ducting - and you will have it in your hands.