I have an 89 4runner 4x4 with a 22re. Ive had a problem with high idle and surging for about a month now and its driving me crazy. Ive read every thread I can find, but none of them have given me a solution. On a cold start it will idle @ 2500 rpm and when it's at operating temp it idles @ 1000 - 1200 rpm. It only surges when its idling around 1500. Ive tried everything, but I can't seem to fix the problem. The idle screw is all the way in, the throttle body is completely closed, the timing has been set 10 degrees BTDC with the diagnostic terminals crossed, the TPS has been adjusted properly, and Ive checked for vacuum leaks using a propane torch. The brake booster looks fine to me.

All new silicone vacuum lines.
EGR delete. There are no emissions restrictions where I live.
New TPS.
New rotor and spark plug wires.
New coolant temperature sender.
Cleaned throttled body.
New PCV valve grommet and breather hoses.
Coolant is full, new dual stage thermostat. Ive burped the system multiple times and there are no leaks.
New water pump.
No CEL codes.
New IAC valve.
New O2 sensor.
Ive cleaned the coolant line that runs from the top of the thermostat to the IAC valve.
Engine has about 5,000 miles on it.
All new gaskets when I put the new engine in.
Has a performance camshaft and the valves are adjusted at .004 and .07 hot. I know they're supposed to be .008 and .012, but there was too much valve noise, so I tightened them up and have had no ill affects.

Any help would be much appreciated. Other than the idle problem, the engine runs great.

 

The brake surging is a common thing/fix. I had it on mine and fixed it.

It slips my mind but I will post again when I remember....

 

Bad brake booster

 

Hmm, maybe a coolant clog somewhere. I had an identical problem where coolant wasn't flowing through because the IACV had a clog.

 

I think I found the problem. I pulled the new IAC valve off and I couldn't cycle the spring. Brought it back to auto zone and got a new one. The problem seems to be gone now.

 

@noahstancik, did you notice and overheat/burp issues when your iac was plugged? reason i ask is every time i drive my 87, if the engine is cold and it will get hot, then burp and be fine the rest of the trip, and i also have the high idle/surging when i brake. i wonder if i have one or two issues.

 

My 22re had the idle surge during braking. I noticed it most during stops at traffic lights. I stumbled across a video in the wee hours of the morning that recommended removing the idle adjustment screw, wrapping it with Teflon tape and reinstalling it. I tried it and BAM, it corrected the issue. Apparently there was a vacuum leak around the threads.

 

^^^That is an excellent tip. I'm going to try it.

 

I've got the idle surge when I press the brake too

 

Mine had the same issue

1 idle set screw apply thread lok and re install

2 brake booster vacuum leak lines or welds

3 most important and most overlooked air in coolant lines run ( from cold ) with rad cap off. Fill and squeeze coolant lines. ( heater core lines are higher ) playing with hoses will help air move thru. The EFI getting hot causes rough idles.