TPS % at idle

It sounds like there's a story behind your question.

The car doesn't even know at first, if the 12 volt battery has been recently disconnected. It has a default % it tries first, hoping the engine will at least start that way, and then it learns what % is needed to get a smooth idle at the right RPM and remembers that.

If you are watching the TPS % on a scan tool, the % you see at true idle, after the car has learned it, is pretty much the answer to your question. Of course, the engine isn't always at true idle: it can also be running at idle RPM, but doing work to charge the battery. The TPS % will be higher then (and you can usually hear the difference in the note of the engine).

 

When we had this code in the 13 persona the first thing I did was swap the throttle body one because it was very quick to do and three by reading it's a known finicky part and other throttle bodies that other Toyota's we've owned have been a little finicky they were not drive by wire but no matter. That immediately cleared up the problem I wasn't really thinking about injectors and the fuel pump and all that too much because the car seemed to run reasonably good just before all this this is also during an engine change in the car so the throttle body that came on the JDM engine was damaged or something internally It gave the 0171 code I believe and I took the one from the original engine bolted it in place and everything was running fine so we left it we thought the lower mileage throttle body on the JDM engine would be in better shape than our original actually not the case.

 

Out of all the things that could cause a P0171 (lean mixture) condition, the throttle body as a possibility would require the most explaining ... normally, the throttle controls how much mixture does or doesn't get into the engine, but isn't in control of how rich or lean that mixture is.

How rich or lean the mixture is gets controlled by the ECM, seeing how much air is being let in (via the MAF sensor) and adding the right amount of fuel (via the injectors).

So a lean condition is usually going to mean there is a place where air is leaking in downstream of the MAF sensor so it isn't being counted, or that the injectors aren't able to deliver enough fuel (their own fault, or low fuel pressure, or out of fuel).

 

I had the part already sitting in front of me I had no leaks and no funny business anywhere It could have possibly been a fuel delivery problem but everything on the cars pretty new and I'm pretty good shape I'm not willing to test individual fuel injectors and a fuel pump generally speaking the car will just die won't be running badly it won't be running at all missing and cutting up and whatnot can be fuel injectors that's true but it seems to be more rare The throttle body in these cars is that drive by wire business I don't know about percentage and all of this nonsense but when it starts acting up the car starts acting weird the minute you change it you can you know it the minute you bolt the other one on and start the car before you even get all the plastics on but that's just my experience here and that's pretty much that.

 

Anything happen to the fuel trims when you give some decent throttle, or are driving at highway speeds?

 

Check the pcv hose on r side of throttle body

 

Did you check the oil filler cap?

 

Mine sits at around 15% when reading the sensor from an OBD2 scanner. I have no idea if that's normal. So take it with a pinch of salt.

 

My Vette reports 30% throttle at 80mph and 7% at idle. Makes no sense. Sounds inflated. But it's inconsequential

 

If u wanna know if u got a vac leak look at fuel trims

 

A Prius engine might be at idle or at "idle". When the power management control ECU wants to put some extra charge into the battery, it will keep the engine at the same "idle" rpm, but load it down to make power for the battery. If you're listening, you can hear the exhaust note sound a little different. The throttle position, of course, is higher at "idle" than it is at idle.

And of course, in a Prius, what you're hearing will be "idle" a lot of the time, because once warmed up, the engine just doesn't idle much if it doesn't need to do anything; it'll just be off.

 

Where do you get these belief systems from