94 4x4 5spd 22re. Bought this truck with blown head gasket so I do not know how it ran when the po had it.

I rebuilt the motor, runs great it's timed perfectly with the jumper wire, idles great when first started (cold start) idles around 12-1300 drive down the road once it's warm idles perfectly at 750rpms BUT if I drive to work 20 miles when I pull in it is idling around 250-350 Roughly some times it'll hang around 500. It's only after a longer drive it does this.

The tps is adjusted perfectly, there are no vacuum leaks I can find, temp is always normal on the gauge
What am I missing? There is no CEL on, I did turn the idle up today to see what it would do I noticed that now if driving at 3000 Rpms push the clutch in the idle drops fast to 500 bounces up too 1100 and stays steady there. When I pulled the motor I cleaned every thing, I pulled the IACV apart and cleaned it but am not sure it's back together right. Is there a way to adjust It or put it together wrong? How far does every thing screw in?

Can some one help I'm getting fed up I can not figure it out!

 

The things i've noticed that affect idle on the 22re are 1- idle adjust screw, 2- iacv adjustment, 3- TPS, 4- miscellaneous things like vacuum leaks, coolant temp, etc, and 5, which everybody forgets about, the DASHPOT! It's the little black plastic round thing on the throttle body that dampens the throttle shutting. They get stuck sometimes and will hold the throttle open sometimes and other times won't. It's basically a shock absorber for the throttle, you can even take it off without any real consequences. That's where i would check, see if while you're idling you can close your throttle more than it already is by just a little bit. As for the jumping idle, if your idle is set really high, since you're off the throttle, the fuel cut circuit will go in and out, cutting fuel when it's high rpm, and putting it back on when you're back at idle rpm.

 

coryc85 has a good write up on his thread about the IACV. Inferno brought up a good point on the dashpot.

Also try burping your cooling system. Get the front end higher then the back by pulling on a steep incline or a high jack and pull your radiator cap and let the thermostat cycle a few times getting the air out of the back of the engine.

 

I had some low/rough idle troubles a while back in my 88 4runner 22re.

So I put a few turns into the idle adjust screw where the throttle cable is (thingamajigger where you loosen a small nut then turn the screw with an allen wrench that rests on a spring loaded one-way air piston whatchamacallit – I think Inferno451 called this the dashpot).

Well the result was that the engine would race for a split second or be slow to return to idle when my foot was off the pedal, like when you shift.

The boot on the whatchamacallit was toast and I think it was actually interfering with this things movement. So I tore the boot off.

I lubed the area up, set the screw to 1/4 turn past just touching the whatchamacallit, and have had no problems since.

Good luck,

 

The boot is torn on the dashpot I have thought of that but was unsure if that could cause it. The fuel cut off makes sense now that you say it.

I'll check out his write up thanks, the coolant system is burped well have tried that but wouldn't hurt to try again.

Before I go to work ill adjust the dash pot and see what my out come is thanks.

 

Taco, did you solve this?

Was it the dashpot?

I'm having cold start rough low idle after a head job:
https://www.yotatech.com/forums/f116...2/index14.html

Adjusted throttle and it doesn't change anything. Everything is fine when warm, but when cold, idles around 100 RPM...sounds nasty.

 

Taco?

My issue is still going on - I've done some adjustments but the long and short of it is:
- I had a rough/low idle on cold starts; eventually it warmed up but it was really a bad cold idle and died a few times (this was with throttle screw and dashpot dialed in per Roger Brown's article)
- I then adjusted my throttle screw another 1/2 turn to make the throttle more open at idle, to avoid the stumbling, low idle when cold. This worked, and I had a cold idle of ~850....but then, when warm, it idles up to 1100 or so and goes into that 1000,1100,1200 and then drop down to 1000 and repeat every 4 seconds...)
- Most recently, I backed off my dashpot screw, taking it out of the equation, and dialed back the idle screw another 1/4 turn (so I'm still 1/4 turn more "open" than Roger Brown says); Now, I have a cold idle that still stumbles, is around 400-500 till warm, then settles in at 850 when warm
- I've used the idle adjustment screw on the TB during all of these trials to adjust the warm idle as close to 850 as I can.

I'm stumped: Shouldn't the engine idle UP when cold, then drop down when warm? That's what the IACV does right - lets more air in when cold, then less when warm, dropping the idle?

I'm hearing that one can open and clean/adjust the IACV - but I can't find threads on it using Google, etc - can anyone chime in if they've done it, and if this is likely my culprit? My truck runs great with the new head, new cam, header, cold air intake - just not when idling cold :/

Thanks

 

Just found this:
https://www.yotatech.com/forums/f128.../#post51643159


Not quite sure I understand the "adjusting the screw after loosening the nut" part...anyone?

 

It's the idle stop screw that the throttle armature (where the cable connects) comes in contact with when the throttle is completely closed.

 

I know how to adjust throttle and have done several times. I'm referring to big blue piles explanation in the link I posted...the yellow arrow part of his post.

 

My bad. I misread it.
It sounds like the adjustment screw is set in a channel rather than a threaded hole. The screw doesn't adjust in and out, but rather side to side and is set in place by the nut.

 

No problem, thanks for chiming in

I just found this thread with some great photos of the inside of the IACV (or AAV):

https://www.yotatech.com/forums/f116...oblems-190304/

No mention of an adjusting screw on the back though, like BBP had mentioned in the other thread I found yesterday. Need to drain coolant, remove and take this thing apart - really curious now!

 

After reading both threads it doesn't make a whole lot of sense to me why it would have an adjustment screw other than to control the idle based on how much air you let pass by, but there's WAY easier ways to control your idle. Seems to me that it should be a fixed position pivot point. I'd like to take mine apart too just to see, but it's hard to justify that when it's working fine as is. I guess curiosity will have to let this cat live a little longer.

 

You can live vicariously through me lol.

May not be soon but I will do this and update