Lowering fast idle at cold start

I did notice The little circle in the top right hand corner of my ultra gauge which is the loop dectector, shows that the loop closes after I have warmed up. Even though I’m only warming up to 164, maybe P.O. put in a lower temp thermostat?

 

Does your truck have a working factory temp gauge? Just curious if it’s sitting in the middle or lower towards C.

 

The gauge operates but I’m not convinced it’s very accurate usually it will get to just under half way, then will drop and It seems to sit at about 1/4 to 1/3 of the way from cold.

I’ll take a picture of my ultragauge and my temp gauge together and post it. I feel like i have seen the factory gauge at the same place when I’ve seen the ultragauge reading both 140 and 165....

I’ve only had it for a few days though, and haven’t had to do all that much driving, so not much accumulated data yet from the ultragauge.

 

I think it still has to get at least 190 to go to closed loop so the computer will actually take over the fuel management/air, again unless things have changed on Toyota's. Do you have a FSM? Also you can check it with a infrared gun, at the thermostat housing and other places. I know in the past, if a vehicle didn't go to closed loop, it'd ruin a catalytic converter eventually because of over fueling.

 

Yes I do have a FSM, but The computer does go into closed loop, the ultra gauge which is a live obd2 reader shows the loop is open when I start her cold, but the loop closes. I don’t know what exactly tells the 3.4l wether or not to close or open the loop but even at 145degrees it will show that the loop closes and then operates as the fsm describes.

I assume The “loop” is “opened” for multiple reasons, if i had a constant open loop, ultragauge would show it. I just learned about the whole loop thing when I got the ultragauge so I’m no expert. It I know the gauge shows it closes

 

I'd be very surprised if Toyota had that cold of thermostat in there by design. Most oil requires 180 min for good lubricity, what does your FSM call for as temp wise on the thermostat. If it's higher than what you're seeing then you have another issue.

Did a little looking at past posts and it seems Toyota used a 180deg thermostat in some of the engines I seen. So that's cooler than most american made cars and way cooler than what I've been use to working on in the past, but still hotter than what you're seeing. So I have no idea if it'd make a difference or not on your situation, worth a try unless it's a bear to get to.

 

Oem is 180.
Granted it doesn’t open till then so really it fluctuates between 185-190.

 

Thanks everyone for your helpful replies. Just seems too high to me at startup

 

The engineers I think knew what they were doing. I defer to their expertise, not a "feeling" you have about what the rpms "should be".

Now, if it idles higher than it used to then you might have a problem, but 1500 sounds very normal to me. Just make sure your normal maintenance items are good to go: plug/wires, IAC, throttlebody, that sort of stuff.