I just Recently purchased a A 95 runner with a 3vz-e. its an automatic 4x4 113,000 miles. very clean truck. From a cold start it idles rough for a couple minutes, (around 1100) then the rpm gradually drops as the motor warms up (which is normal i know) but heres my issue. When the engine is warm it dips down into the 600 Rpm range out of gear, and when in drive can dip as low as 450.
I started trouble shooting the problem and found that the vacuum line running from the egr vac module to the egr valve was snapped, i replaced the line and cleaned the module filter. this fixed the rough idle on start and reduced a significant amount of valve noise but did not resolve the low idle.
The idle does not surge.
It started to idle low all the time, from start as the engine warms.
I tried to adjust the idle with idle screw put it didn't seems to do anything.
I've ran injector cleaner through it and tested for vacuum leaks but nothing has turned up.
Any Ideas n what this could be?

 

Have you checked the ignition timing ?

 

On under hood driver side is the vacuum hose routeing decal. When removeing the plenom to get to valve cover or replace pcv
on passenger side, the three hoses in center must be reconnected correctly to the vsv's. Sometimes you will get a code 71 and vacuum lines. Do a search in the search box.

 

Adjust your TPS with a multimeter and a feeler gauge:


http://personal.utulsa.edu/~nathan-b...93throttle.pdf