DMagz

In October I decided to flush my antifreeze on my 94 Toyota 22RE, 4x4, 5spd. w/AC and w/about 149000, cause it looked horrible. So I flushed it, new hoses and thermostat and burped the crap out of it. Since then I've been chasing after a surge that: It starts fine, idles up around 1300rpms until it's warm then back down right around 750rpms. Jump in it and drive it and what I notice is if I'm sitting parked with the engine idling, the idle starts to pick up to between 1000rpms to about 1400rpms, then it drops to 500rpms and starts to surge.
What I hear: The valve in the air flow meter stays partially open, from what I can hear cause it makes a gurgling sound and when I unplug the vacuum switch with the orange and black thingy on it (top of the valve cover), it stops the sound. Also, if I have the heat on, it'll go cold during the surge and my overflow jug will start to fill up. I have checked every freakin' possible thing under that hood. I've replaced the Idle Air Control Valve, checked every vacuum line, tuned it up and went crazy as well. Please, I need someone to help me with this. I've been reading every blog on the internet about surging Toyota's and none of the information has helped! Talked w/my Toy mechanic and he's at a loss too.

Jay351

You have air in the cooling system. It will cause a gurgling sound and idle surge.

Get the front end up nice and high (I park on my slight inclined driveway and jack the front of the truck up a good foot or so), remove the rad cap, set the heater to hot and start the engine. Run it from cold till its normal temp is reached. If done correctly all of the air bubbles will be gone and you will have to add coolant.

Be carefull not to overheat the head and warp/crack it. Air bubbles mean less circulation, if any in the cooling system..

DMagz

The gurgling sound is from the airbox, not the cooling system. I've spent hours and tons of antifeeze/H20 burping the truck and even the mechanic pressurized the system to take the air out and it still surges. The sound is like a throaty gurgle, from the airbox and when I disconnect the vacuum line on top of the valve cover, with the orange/black thingy on it, it stops the sound from the airbox. When it's surging, it sounds like I've got a muffler in the airbox, which I've also replaced.