Idle at 1500 rpm after cleaning IAC

[Pyral]

I cleaned out my IAC and throttle body of carbon, I also clean what I could reach inside the intake of carbon as well. I replaced the gaskets, reattached the throttle position sensor that was dangling by a single screw.

I also removed the throttle stopper because I thought I needed to remove it to get to a bolt, but I counted threads when I put it back. Some of the hoses split up to the clamp when I fit them back over, but I don't think they'd be leaking.

After putting everything back together, the idle is at 1500 rpm warm, and I don't have any engine braking. When I pull the throttle back even further, I can make it drop to 1000 rpm, but this phenomena was a thing when my 4runner idled at 700 rpm.

What should I look at and how should I check for vacuum leaks?

 

[brillo_76]

Check it over... When i cleaned mine in the vehicle. It took a few days for the idle to clean itself out and function properly. At first I thought I damaged it.. Then in a few days it worked properly again. It would idle at 1500 1400 rpm for a while before it settled down.

 

[phattyduck]

Did you make sure the IAC moves through its complete range smoothly after you were done cleaning it? Sometimes bits can get stuck in there and it can't adjust like it is supposed to.

Make sure your throttle plate fully 'snaps' shut if you quickly release the throttle. If the cable is holding it open, you need to loosen the cable.

-Charlie

 

[Pyral]

I think I found the problem, the cable was slack enough to bottom out at the startup throttle position but not at the operating idle point. So the cable appeared good until the engine started, the vacuum plunger that sets the startup throttle would suck in, and then and only then could you see the cable was too tight.

I unhooked the cable completely and my idle went down to 1000 rpm, about what I'd expect on a partially warmed up engine. So I must have set my cable too tight, an easy fix.

Edit: adjusted and drove it, idle is back to normal

 

[phattyduck]

That dashpot/throttle opener is only there on the manual trucks (V6 has a similar one), so many of us would have missed that.

-Charlie

 

[TheDurk]

That dashpot/throttle opener is only there on the manual trucks (V6 has a similar one), so many of us would have missed that.

-Charlie

It was the first thing I thought of. One time I cleaned the IAC and did not push the vac hose back on to the dashpot thingy. Hose was just resting on the nozzle so it looked good, but lost vacuum. Took a while to find.