The car idles too low and stalls when you release the throttle

SOURCE: 1984 Toyota tercel wagon

Although this isn"t a proper fix, and may affect emissions, I ran accross this problem on a friend's 87 2wd wagon.

There is a dashpot that controls a lever the Idle set screw is on, I am guessing it is a decel valve that closes butterfly when coasting in gear. I never looked at a manual to figure out what controls the vacuum valve that is on the passenger side of the engine compartment, but if you disconect the vacuum line and plug it that lever will not back off and idle will remain where you set it with the adjustment screw.

Make sure the engine is warmed up and not on a fast idle cam before adjusting idle.

The car is a 5 speed, I not sure if automatic cars are the same.

The car idles fine now and still run's great and gets 37+ MPG with 240000 miles!

If you want to fix it properly you would have to diagnose why that dashpot is being actuated at idle

SOURCE: car won't idle after battery change

Won't idle after battery change... SOLVED! well, for me anyway. :)

I just experienced the same problem on my 2002 tundra last night, and fixed it this morning after sleeping on the problem. Here's how it went.
I cleaned the terminals, etc., and replaced the battery, as it was 7yo and old and on the verge of failing.
Immediately after this, the truck would start right up but the idle would drop to about 100 RPM, then slower and slower, and eventually stall. Every time.
I warmed it up and drove around the neighborhood for about 45 minutes, thinking the computer needed to re-learn it's Idle settings, etc... No change.
This morning, I decided to go after the cheap and easy fixes first...
Inspect throttle body... it was filthy full of black sticky dirty/sludgy stuff. I cleaned it off using a rag and some brake cleaner. DID NOT spray brake cleaner IN the opening; just on the rag and then wiped all of the gunk out of the opening, butterfly, and inside as far as my fingers would reach with the butterfly open.
Reassembled everything, started truck... runs perfectly.

Dead battery? Won't run? Dirty throttle body? How do these all tie together?! Here's why (to the best of my understanding).
Over the past 65k miles, dirt and gunk slowly but surely builds up in the throttle body. At some point, the computer senses that this affects the air/fuel mixture or something of this nature. The computer compensates for this, and stores it to it's memory. Sometime during the vehicles lifetime, the battery fails or is disconnected. The compensation settings that the computer stored are lost when the power is disconnected, so the next time the engine is started it's telling everything to behave as default... but the car isn't in a default state, there's **** in the throttle body... or a bad sensor, etc.
I could be way off, but my gut feeling is that this is correct. My advice: Pull the intake tube off the front of the engine and clean the gunk out of the throttle body. It should be the first thing to try, since it's the cheapest and easiest thing that I can think of.

SOURCE: idle to low

The idle is electronic, possible causes of this could be the idle air control valve, mass air flow sensor, and air hose from filter. You can verify if there are any leaks in your filter housing with a visual inspection, you can also remove the mass air flow sensor very easily and see if it is clogged with dirt.

SOURCE: 2003 toyota sienna idle problem

After about 100K + miles the idle air control valve (IAC) begins to collect carbon deposits that interfere with the movement of the spring-loaded valve. You will not be able to clean this without removal and dissembly of the IAC body. Use an emory cloth or fine sandpaper to remove the build up around the valve. This should free it up to rotate without binding. This is a temporary fix, of course, and will either require cleaning again or replacement of the valve. Getting to the IAC requires removal of most of the intake upto, but not including, the intake manifold. Total time is approximately 3-4 hours, but worth it. Good luck, and I hope this helps.

SOURCE: 1999 Toyota Camry V6 idles rough and stalls after

yes it could be a fuel related problem, when was your last tune up, it could also be a spark issue, old or corroted spark plugs will sometimes not put out the correct amount of heat to ignite the gas correctly till it runs for a while, if the check engine light isnt lit, it will almost have to be something simular to this