From my experience with bad idle here is a brief list of items to check:
-TPS
-MAF
-Vac Leaks
- PCV valve
- IAC !!!
- throttle body functionality
- Throttle cable
- Dashpot
- idle screw
- O2 sensors
- Engine Timing
- Air filter
- Spark plugs, dist cap, wires etc.

 

Here's a stupid question. Is the idle in the 3vze supposed to remain constant when there's load on. Like shifting from neutral into drive. I know there's an "idle up" switch of some sort for the a/c, but my a/c doesn't work (don't really need it). Anyway, mine doesn't, the idle drops under load a few hundred revs. Normally I would go looking for a faulty iac valve, but alas, there is none. Not really too sure how these engines compensate load for idle control. I have searched and looked through the manuals, but haven't really been able to glean a great deal.

 

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i did that, and it fixed my problem, so what does that mean?

 

It means you either have the vacuum lines connected wrong, your vacuum distribution "puck" (beside the EGR...don't recall the real name) is not working properly, or the VSV on the passenger side fender well is not functioning. There areare procedures for testing in the FSM.

If your state has no emission testing, you can plug that vacuum line up & insert a 10,000 ohm resistor (radio shack) into the EGR plug on the wiring harness to prevent Check Engine light. First, I'd make sure the vacuum lines (probably the 3 under the Cold Start Injector) are correct.

 

OK, this may be the dumbest question cause I feel dumb asking.

This is the first Toyota truck I have ever worked on, just got it and am checking things over. Trying to hook up my tach to check the idle, which seems a bit high. Where do I hook up the tach? I know one is ground and one is on the coil, but there are no posts on the coil to attach the gator clip to.

Thank you,
L

 

Located the cause of surging ( 1500 to 2000 rpm) on my 1990 4runner 22re last night! I think..... Once it's warm the surging starts and I was able to lower the idle to 1100 rpm but had to screw the idle air screw completely closed to do so. This stopped the surging. From what I've learned on this GREAT FORUM this points to a stuck open IAC valve. My question is, is it worth my time to attempt to clean/unstick the IAC valve? I have the one in the truck now and another from a parts engine and a can of brake clean is a lot cheaper than a new valve (saw one for $150 online and that didn't appear to be a quality unit). Thanks.

 

For anyone that read that last post it was definitely worth it to clean the iacv! Clogged port on the outlet side of the valve.... Truck currently purring at 650 rpm!!