idle too low, car sometimes dies (yes i searched)

[ninja771]

2VZ-FE engine, so no manual idle adjustment...here is what happens:

on warm starts only, my idle will on occasion drop below 500, causing the engine to sputter and vibrate.

If i blip the pedal to get it back up, it will either die or go even lower than it first was. (If it does die after this, restarting the car solves the problem and the idle is ok again (750rpm)

I was messing around with it one day to keep it from dying and at a stop light i had held the gas steady at around 1,200rpm, when i let off the gas to go from N to D, the car simply just died. I can repeat this every time the car is warmed up and i am sitting in any gear.

What i have already checked/done after this issue arose:

-TB and IAC are clean as a whistle (i regularly clean them)
-Replaced external ignition coil and primary ignition wire.
-Swapped TPS, no difference.
-Spark plugs are only about 6,000 miles old.
-Checked for vacuum leaks, none.
-AFM is ok because i tested with 3 different used ones and i still have the problem with all of them. (this was my dealers diagnosis, glad i didnt go with them and replace it for 600 bucks).
-Got a new transmission...but i doubt that matters.

Any help is appreciated.

[Bdub215]

Originally Posted by ninja771

2VZ-FE engine, so no manual idle adjustment...here is what happens:

on warm starts only, my idle will on occasion drop below 500, causing the engine to sputter and vibrate.

If i blip the pedal to get it back up, it will either die or go even lower than it first was. (If it does die after this, restarting the car solves the problem and the idle is ok again (750rpm)

I was messing around with it one day to keep it from dying and at a stop light i had held the gas steady at around 1,200rpm, when i let off the gas to go from N to D, the car simply just died. I can repeat this every time the car is warmed up and i am sitting in any gear.

What i have already checked/done after this issue arose:

-TB and IAC are clean as a whistle (i regularly clean them)
-Replaced external ignition coil and primary ignition wire.
-Swapped TPS, no difference.
-Spark plugs are only about 6,000 miles old.
-Checked for vacuum leaks, none.
-AFM is ok because i tested with 3 different used ones and i still have the problem with all of them. (this was my dealers diagnosis, glad i didnt go with them and replace it for 600 bucks).
-Got a new transmission...but i doubt that matters.

Any help is appreciated.

I don't know if the 2vz afm has an adjustment screw for the blend door but if it does screw it 2 turns counter clockwise and see what happens. I had a similar issue in my 3vz (normal idle but sputter, misfire, bog) give it a shot.


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[holmesnmanny]

Hey, mine used to do the same exact thing. I think it was related to the EGR valve being dirty and clogged. Also, I believe the vacuum hose that runs from the modulator to the EGR valve was leaking because it was old. I did a lot of stuff at the same time and it doesn't do it anymore so I'm not certain which one fixed it but I'm guessing it's the EGR valve being clogged. But occassionally it would throw an EGR code. Buy a couple EGR valve gaskets and then pull the valve and carbon clean the hell of it with some carb cleaner. Also, try replacing the vacuum hoses that go around the system. I bought an 8 foot long bulk OEM hose from toyotapartszone for 36 bucks when I bought a bunch of other stuff so I saved money on shipping and I replaced all of my vacuum hoses while I was at it. Try just gently pulling the little vacuum hoses and see if one of them is really loose at the end.

One more thing I did was I pulled the EGR temperature switch. It's a 14 mm bolt. Then I cleaned the end of it with some carb cleaner. Mine had some carbon soot on the end of it about a quarter inch thick.

[ninja771]

Thanks! Ill try those out. I know 2 years ago i had my EGR cleaned bc it failed emissions...but maybe two years of crap will do it.

[ninja771]

No screw to adjust anything on the AFM. Im working on cleaning out all my vacuum pipes now.

[joeykrim]

Hopefully you resolved the issue.
If not or anybody else browsing through this thread with these symptoms .. I had most of these exact same symptoms and turned out to be my battery was dying.
I'm embarrassed to admit it but hopefully it will same somebody else the hassle as I went through all the troubleshooting steps above and even had the fuel pump replaced and idle adjusted only to find out it was the battery!