idle adjustment screw?
Jan 30, 2011 | 10:20 AM
#22
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22RE throttle stop screw
22RE & 3VZE idle speed adjusting screw
Last edited by MudHippy; Jan 30, 2011 at 10:30 AM.
Jan 30, 2011 | 10:36 AM
#23
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From: Wilkes-Barre, PA, USA
right, but.. unless you've done something like change intakes, cams, headers, exhaust, timing etc etc and it caused an idle change, there really should not be any reason whatsoever you should have to touch either one. Oh all of a sudden my idle changed and people telling others mess with the speed screw or stop screw, it's ridiculous.
Jan 30, 2011 | 11:37 AM
#24
If it's done it since he has owned it and hasn't got an idea as to the problem I would check to make sure everything is to spec as per Factory Service Manual. Who knows what the previous owner messed with, he could have messed with the idle stop screw or loads of other idle changing things.
Jan 30, 2011 | 11:44 AM
#25
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right, but.. unless you've done something like change intakes, cams, headers, exhaust, timing etc etc and it caused an idle change, there really should not be any reason whatsoever you should have to touch either one. Oh all of a sudden my idle changed and people telling others mess with the speed screw or stop screw, it's ridiculous.
Or, in the case of the idle speed adjusting screw, the o-ring is damaged/cracked/shrunk and is leaking air into the by-pass circuit. In which case you should replace the o-ring and re-adjust the idle speed. Or, if the by-pass circuit becomes partially clogged. In which case you should remove the idle speed adjusting screw, clean it and the by-pass circuit with carb cleaner, then replace the screw and re-adjust the idle speed. Of course you could, in both instances, get away with not fixing the real problem, and just making the necessary idle speed adjustments with the screw. For a short while possibly anyway.
Either of those reasons(o-ring or blockage), or any of the reasons you've provided, are why the idle speed adjusting screw isn't capped at the factory(like the idle mixture adjusting screw on the VAFM is), and the instructions are provided in the FSM on how to adjust it(and aren't provided in the FSM for the idle mixture adjusting screw, which is never meant to be adjusted).
Why is this so?
Because these engines aren't equipped with an ISC(Idle Speed Control)system by which the ECU is in total control of the idle speed while the engine is at operating temps. So that's the only way to correct the idle speed if it were necessary to do so, for whatever reason(be it real or imagined). The IACV(Idle Air Control Valve)/auxillary air valve only raises the idle untill operating temperature is achieved. And the A/C idle-up valve or throttle opener, if equipped, is only used to raise the idle speed when the A/C is in use. Neither of which does the ECU have control over. The IACV/auxillary air valve is controlled by the coolant temperature, and the A/C idle-up valve or throttle opener is controlled by the A/C amplifier module. There's also a power steering idle-up valve, which is controlled by the pressure of the fluid in the power steering pump housing.
Last edited by MudHippy; Jan 30, 2011 at 02:22 PM.
Jan 30, 2011 | 02:36 PM
#27
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You don't, or rather, you can't. That's a function of the IACV only, which is entirely unadjustable. That's why the instructions for setting the slow idle speed say to do so after the engine has reached normal operating temperature. So that the IACV will have no affect on it, as it's fully closed once the engine warms up.
Base/intital ignition timing might have a small affect on it, but it will have a larger affect on the slow idle speed. So by resetting the slow idle speed(with the idle speed adjusting screw)after a change in base/initial ignition timing, the fast idle speed will also be corrected equally.
Base/intital ignition timing might have a small affect on it, but it will have a larger affect on the slow idle speed. So by resetting the slow idle speed(with the idle speed adjusting screw)after a change in base/initial ignition timing, the fast idle speed will also be corrected equally.
Last edited by MudHippy; Jan 30, 2011 at 02:48 PM.
Jan 30, 2011 | 02:47 PM
#28
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From: PDX
when the thing is acting up and idling high try pushing the throttle body closed manually (under the hood) to see if your idle goes back to normal. On the 22RE's, it's fairly common for the throttle body dashpot to start sticking. This can also sometimes cause a TPS code to pop up since it prevents the throttle from closing all the way (ECU sees the "throttle closed" terminals never make contact and assumes a TPS problem, hence the code). I've always just removed the dashpot completely (2 philips screws) with no ill effects, some people say you can clean and lube it to make it work properly
LINK
Notes:
Dash Pot:
The GREEN CIRCLE shows the dash pot (DP) which is there to slow the closing of the throttle to prevent backfiring. It consists of the round air bellows, a spring loaded plunger, and the air vent line that attaches to the fitting at the base of the bellows. The vent line has a check valve in-line and an air filter to keep dirt out. The check valve lets air into the bellows then the throttle opens and extends the plunger. When the throttle closes, the stop screw contacts the plunger and pushes it in. The check valve closes to slow the air escaping the bellows and thus slow the closing of the throttle.
To troubleshoot the DP, make sure the air filter is clean and make sure the check valve is not clogged or stuck open. You should be able to blow air into the bottom easily (filling the bellows) but it should be hard to suck air out. Both the filter and valve can probably be cleaned with a mild solvent. Also, the plunger can stick. I find a shot of silicone spray applied to it periodically helps keep it moving freely. Lube it the push it in and out fully a few times to work the lubricant down into the plunger. And you can simpy back the adjuster screw all the way back to keep it from contacting the throttle linkage as a test. This way it is eliminated from affecting the throttle operation, in case you think it may be causing a problem.
To adjust the DP, I find setting the stop screw to depress the plunger about 1/2 of it's travel works well. If set too deep, you have more spring force to overcome and that can cause the throttle to not fully close. Too shallow and the DP can't really do it's job.
Originally Posted by 4crawler
LINK
Notes:
Dash Pot:
The GREEN CIRCLE shows the dash pot (DP) which is there to slow the closing of the throttle to prevent backfiring. It consists of the round air bellows, a spring loaded plunger, and the air vent line that attaches to the fitting at the base of the bellows. The vent line has a check valve in-line and an air filter to keep dirt out. The check valve lets air into the bellows then the throttle opens and extends the plunger. When the throttle closes, the stop screw contacts the plunger and pushes it in. The check valve closes to slow the air escaping the bellows and thus slow the closing of the throttle.
To troubleshoot the DP, make sure the air filter is clean and make sure the check valve is not clogged or stuck open. You should be able to blow air into the bottom easily (filling the bellows) but it should be hard to suck air out. Both the filter and valve can probably be cleaned with a mild solvent. Also, the plunger can stick. I find a shot of silicone spray applied to it periodically helps keep it moving freely. Lube it the push it in and out fully a few times to work the lubricant down into the plunger. And you can simpy back the adjuster screw all the way back to keep it from contacting the throttle linkage as a test. This way it is eliminated from affecting the throttle operation, in case you think it may be causing a problem.
To adjust the DP, I find setting the stop screw to depress the plunger about 1/2 of it's travel works well. If set too deep, you have more spring force to overcome and that can cause the throttle to not fully close. Too shallow and the DP can't really do it's job.
Jan 30, 2011 | 03:02 PM
#29
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I suppose a quick check for a code 51 would all but rule out that possibility. Maybe not entirely, so a thorough check of the functionality of the DP would also be in order.
Pages EG1-198 & EG1-199: http://personal.utulsa.edu/~nathan-b...34throttle.pdf
I removed the DP on my 3VZE once. BAD IDEA!!! Engine did not like that one bit. Damn thing bucked and heaved like a raging bull! Every time I let off the gas and then got back on it at slow speeds the thing bucked and jerked so hard it almost gave me whiplash. So I put it back on...won't do that again.
Might be different with a 22RE, though I don't see how.
Jan 30, 2011 | 03:11 PM
#30
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From: PDX
I suppose a quick check for a code 51 would all but rule out that possibility. Maybe not entirely, so a thorough check of the functionality of the DP would also be in order.
Pages EG1-198 & EG1-199: http://personal.utulsa.edu/~nathan-b...34throttle.pdf
I removed the DP on my 3VZE once. BAD IDEA!!! Engine did not like that one bit. Damn thing bucked and heaved like a raging bull! Every time I let off the gas and then got back on it at slow speeds the thing bucked and jerked so hard it almost gave me whiplash. So I put it back on...won't do that again.
Might be different with a 22RE, though I don't see how.
I don't get any bucking on my 7M without the dashpot, but i do get a very light "pop" through the exhaust on initial decel. I don't remember my 22REs even noticing that the thing was missing, but that was awhile ago and my memory might have faded a bit.
Last edited by corax; Jan 30, 2011 at 03:12 PM.
Jan 30, 2011 | 03:17 PM
#31
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Yeah, the funny thing is mine don't work at all. By which I mean it doesn't pass the test and definitely doesn't prevent the popping in the exhaust on deceleration. That's why I figured I'd just remove it. Well...I learned real quick, broke or not, it does do something still.
Last edited by MudHippy; Jan 30, 2011 at 03:19 PM.
Jan 30, 2011 | 04:44 PM
#32
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From: Vegas
Mine will cold "idle" from about 1400 up to 1900 it seems. Based on coraxes post yesterday I went and removed the dash pot....think it was hanging up a bit at times... timimg is advanced 2* from stock, doubt thats why it idles fast though . Along time ago, when sis owned the Runner, I had to play with the idle speed adjusting screw on top of the throttle body, so the A/C compressor engagement wouldn't make it rev so high like it did, maybe thats still off ??? Hot idle is fine at ~750-800~
Jan 30, 2011 | 05:07 PM
#35
Then, the box behind the glove box is used to set my kick in A/C speed then ??
Jan 30, 2011 | 07:24 PM
#37
Mine will cold "idle" from about 1400 up to 1900 it seems. Based on coraxes post yesterday I went and removed the dash pot....think it was hanging up a bit at times... timimg is advanced 2* from stock, doubt thats why it idles fast though . Along time ago, when sis owned the Runner, I had to play with the idle speed adjusting screw on top of the throttle body, so the A/C compressor engagement wouldn't make it rev so high like it did, maybe thats still off ??? Hot idle is fine at ~750-800~
Feb 2, 2011 | 07:45 AM
#39
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From: Birmingham, Al
Ha, I have similiar issues...Idle is fast, timing is right, and when I hit the brakes, engine bogs down. Anyone have a good pic of this idle speed adjusting screw. I was turning the AC knob like an idiot. I have the 88 FSM so I plan to look there too.
Last edited by TJ96TLC; Feb 2, 2011 at 07:48 AM.
Feb 2, 2011 | 08:13 AM
#40
