ENGINE WON'T STAY RUNNING

Of course the engine is designed to shutoff after it warms up. Original battery? Have you checked the 12v dc with a meter? A severely discharged and old battery can drag down the 12v such that odd things occur. You could remove it and have it load tested at an auto supply. Finally, it often takes a couple of tries to Ready the car after the 12v has been discharged or disconnected.

 

First thought is that the throttle body needs to be cleaned. With normal engine operation, oil vapors condense on surfaces inside the intake manifold and throttle. Over time that oily film bakes into a carbon sludge inside the throttle bore right where the butterfly valve blade is when closed.

This restricts airflow some, but the ECM can compensate and adapt by opening the throttle just a little more at idle to keep the engine speed up. The ECM stores this adaptation data in special memory. When you disconnect the 12V battery, that memory is cleared and the ECM resets adaptations to "new from the factory" presets.

If the throttle does have a build up of goo then it can't flow enough air when it's at the factory values, so the engine can't run correctly- if at all.


Posted via the PriusChat mobile app.

 

This is "normal" if you have not installed an Oil Catch Can. Overfilling the oil even a tiny bit would make such sludge worse.

 

With my Prius, the engine will NOT rev up if it is in PARK, maybe Neutral too.

Then just because your battery "tested good" once does not necessarily mean that it IS good.
It still may not be fully charged either.
Charging it correctly would take several hours.
If a shop said they did it in 10 minutes.......they lied.

If the battery is over 5 years old, just get a new one......and check the OTHER end of the main cable connections too.
After installation, check the charging voltage while the car is running (READY).

 

Mine will increase the engine RPM some if you press the go pedal in park. Just up to a sort of moderate RPM.

Being throttle-by-wire, of course it doesn't feel much like revving a conventional car. It's very obviously a case written into the computer code for "hmm, driver is pressing go pedal in park. Humor him and increase the RPM a bit."

I have used it to reach operating temp faster after coolant changes, and in the water pump experiments, so it's not completely a useless party trick.

 

March 2019 post

The op has started four threads since 2019 and has never responded to anyone's replies.

 

The ICE isn’t running. Those :30sec “run” periods are the HV battery trying to start the ICE by spinning it rapidly so it sounds like it is running. Too many more of these failed starts will drain the HV battery beyond its minimum charge (that’s a very bad thing).

How long have you owned this vehicle? Previous history?

 

So, it gives us an excuse to yak among ourselves, and maybe something interesting comes out for somebody who reads it later.