uneven throttle response in cold weather

This happens to me when the engine is not fully warmed up. When it hits 103F full power is had and if your pedal is in the floor, your are going to feel a surge.

Otherwise with a fully warmed engine, acceleration is very smooth.

Welcome to the forum by the way!

 

I have not experienced this yet.....have had several cold starts...

 

This is normal, what the car is trying to do is let the ICE warm up at a set rpm, and use the battery as much as possable for power. But their is a certin spot where it can't provide the power your asking for then it just lets the ICE rev up. This all goes away once the ICE hits a certin temp. When it is warmer it will just rev up the ICE all the time to provide the power needed.

For the posters that have not noticed this, with a warm car taking off the ice will start and the harder you push the pedal the higher the ICE rpms, but when the ICE has just been started you will notice the ICE pretty much stays at a certin rpm, untill your asking for to much power the it will let to ICE rev up.

What the OP has posted sounds just like my car, I think if you think it is unsafe that Toyota has set the car to use battery power as much as the car can untill the ICE is warm, you will have to get rid of your car. I don't know the real reason for it though, maybe to protect and extend the life of the ICE from higher revs with cold oil or maybe it to reduce emmisions because certin parts of the car are not hot yet and can't provide the great emmisions the car does when it is warm. Maybe other can answer this question.

 

Your not the only one with this "problem", I left my 2010 off at the dealer Sunday and went down yesterday morning to go out for a ride, we got in the car and he sat there while it ran for about 2 minutes while he was pushing buttons and looking at this and that, then we roamed around the parking lot for 2 more minutes and went out on the street and he took off at a very slow pace , it seems according to the tech I don't have a problem. So now at 10 to 20 degrees I have to sit in the car and let it warm up for 3 or 4 minutes and then get out in traffic

 

It's just an idiosyncrasy of how the car warms up. For those of you old enough to recall carburetors, remember the "fast idle" setting? Because cold engines didn't idle well, a spring on the carburetor would keep the idle fast until the engine warmed up. Our old Camaro would idle at 40 mph on a cold day.

It's a bit similar with the Prius, although now it is all done with software. Cold engines are not very efficient, and they tend to produce more emissions. The Prius tries to avoid using the engine when it is cold, and instead relies more on the electric motor. This makes it feel sluggish on a cold morning.

If you press it, it will reluctantly switch to the gas engine, even when cold. When it does, the engine makes a bit of a racing sound and you get a shot of power.

There is no need to wait for the engine to warm up, unless perhaps you need to make a jackrabbit start into traffic. Otherwise just drive, but try to take it easy.

Tom

 

I've not noticed uneven engine throttle and acceleration, but in my part of NC the temps don't get real cold (good grief! accept right now) and I garage my car.

I just drive the car without regard to hot/cold engine performance, but I do know enough to "take it easy" when the engine is cold.

Happy Motoring!

Tom

 

I am old enough to have driven 1/2 the cars i've owned having carbs, but this Prius seems to be all or nothing in traffic when cold, I think it's the jack rabbit jump that is the real problem when trying to stay up with traffic in rush hour thats a problem. I went back to the dealer this morning and this time I drove the car cold in traffic and they finally agreed that something should be done, They have contacted the zone rep and will get a claim number and we'll see what can ( if anything) be done about this other than finding a different way to go to work that would let the cold engine warm up, they did offer a block heater I'm just not sure this is the answer, is their a remote start for the Prius??

 

The block heater would help if let soak for 2+ hours before you left. There would still be a minutes worth of warm up to get it through the first stages though. There is an OEM remote start as well. That would help too.

 

I am having the same problem. Got my Prius in sept. 2009 and it has 21k miles on it. I swear it didn't do that last year. Its seems like it would be called hesitation in a regular gas engine car. One thing that would be different is that I'm probably pulling out faster than last winter, since it was still really new to me and I was babying it. Going to try slower acceleration and see if it goes away. Its fine after the engine is warm.

 

It's intriguing to read how newer owners have become so accustom to the smoooooth feel of a CVT that any type of "shifting" sensation is perceived as a problem. In the past, people use to complain about the opposite. Times have obviously changed.

Prius using the electric-motor more to increase the longevity of the gas-engine during warm-up is nothing new. I've noted it with all 3 generations over the past decade. In fact, here in Minnesota that seasonal change is what I've become accustom to.

In short, nothing's broken. That's how it was designed to operate.
.

 

Also, have you noticed the transition when dropping to 2-bars while climbing a hill?

The engine will kick into heavier use then too.
.

 

Mine does it, since i have to go up a large hill with a 60mph limit within 100 metres of my driveway. Letting the engine warm up, and getting to the hill slowly both help. The real big difference i've seen is SOC. If i start the journey with 2-3 bars then it's really painful. if i start with 6-7 then the hill will take me down to three, but i don't get as much horrible pulsing from the engine.

Block heater would be a massive help, i'd definitely take that option!

 

You guys should get a scan guage and watch the ICE rpm's. It will show you whats going on.

The car is trying not to spew losts of emissions into the air, and to protect it's self. But if you do try to take off fast the car will give in at a certen point and let the ICE rev up hard and fast so you still have full power this is the surge you feel. But it really just wants to use part ICE power bigger part battery/electic motors to power the car untill the ICE hits a temp. Then the ICE will rev up and down like it normal does.

 

My 2006 Gen II does it.

Tom