jonb

Hello,

Have a 2000 4runner, 6 cylinder, 2wd, about 75k miles..
Was having some hesitation and hard starting problems so I recently gave it a tuneup which included:
spark plugs
air filter
cleaned MAF sensor
cleaned intake (butterfly)

Now the hesitation on acceleration is gone but the low idle/hard starting is still a problem. No problems when cold-the engine starts and idles just fine. The problem occurs when the engine is warmed up, turned off and then restarted before it becomes cold again.

The engine will start when warm but idle about 400rpm on the verge of dying. In park, gently accelerate to 1500 or so rpm and then release the accelerator--rpm's drop down again to about 400rpm. Instead "goose" the throttle to above say 1500 rpm's--engine idle will then drop down to its normal 650 or so rpm and idle is steady and smooth.

Idle is smooth after that and the vehicle runs and accelerates flawlessy. Battery is pretty new and has tested to be in good condition. Have hooked up code reader and there is no DTC or check engine light activation. Any clue as to what is going on here?

thank you,Jon

BajaRunner

This is a common problem. It is the IAC (Idle Air Control) that is killing it for you. Try searching on it here. I don't have a good link for you. All you need to do is clean it.

Basically all you need to do is take off the throttle body, and right below you have a few sensors that connect to a magnetic device of the IAC. It just controls the air intake at idle. Just like your throttle body, it gets a ton of gunk in there, and you need to take some carb cleaner or some sort of cleaning agent and scrub it down with a tooth brush. You'll see all the dirty crap come out. Once thats clean, then you're good to go. I just did this a month ago, and it is like night and day. When I start the truck up it ROARs like it should be at a warm idle.

jonb

Sounds good--thanks for the advice. A few questions since you've done this before...

1. Is there a suggested procedure or tips/hints for doing this? I searched but was unable to come across any detailed instructions for cleaning the IAC.

2. Do you need to disconnect the throttle linkages from the throttle body?

3. Got the gaskets I need to replace--do I put any sort of gasket sealant on the gasket itself?

thanks for any help. Jon