Need some thoughts on this

[DukesFist]

I got my new 2016 Fiesta a couple weeks ago and it has 600 miles. I have noticed everyday when I leave work the car just falls on it's face. When I pull out of the parking spot, when I try to go up the grade in the parking lot and when I pull out into traffic the car just falls flat on it's face. It acts like a manual choke car that needs full choke and it only has half. The car works great in the morning as I can start it and let off the clutch without giving gas and it will pull out of the driveway wouldn't even try that in the afternoon.

Would the a/c drag it down that much? Or is this something else?
Thanks for any help
Duke

 

[jeffreylyon]

This happens just when you're coming off of idle from a stop or everywhere in the power band? Does it get better with revs?

 

[DukesFist]

It happens just off idle i.e. pulling out of the parking space or pulling into traffic then once I get going it's fine. I had no problems this morning coming to work it just seems like it happens only when it is really hot like when I get off work but then as I make my way home it gets better. It acts like a car in the winter where it needs to warm up before it will run right except this is the opposite, it does it warm.

 

[jeffreylyon]

Well, I'v got a 2016 and run the A/C in the afternoon and don't have anything similar. The only difference I notice when I run the A/C is that it's cooler and a little more vibration (I've got a Cobb RMM) - no noticeable changes in throttle response.

 

[ed_the_sledd]

Something similar to this happens to me as well. Usually when I'm pulling on to traffic, I feed the throttle to take off and the car kinda brakes or stumbles before picking up speed. I believe this happens because I let go of the clutch too quickly though. This is my first manual car so I don't have too much experience, but I imagine that if I let go of the clutch too quickly with not enough gas, then the load of the car and low power causes it to stumble. The turbo isn't spooled up at that point so all of your torque comes from the almost NA 1.6 liter engine, which is not a lot. I also think it happens more frequently when traction control is on. If I turn it all off, then it doesn't really happen anymore, but maybe that's also because I drive faster/harder with TCM off. I think you should try to either let go of the clutch slower or give it more gas. Maybe even try turning off traction control as well. Hope this helps

 

[DukesFist]

I appreciate the input. When I leave work the A/C is usually on max because it has been over 100 with the heat index. I am going to try to just put the windows down today and not have the A/C on until I get going down the road. I usually have the car in sport mode so I don't think that is it and I have been driving manual trans. cars for over 30 years so I don't think that's it. I really feel I should be able to run the A/C in the car on a hot day but I'll try it just to see.

 

[Hijinx]

The issue is heat soak. There are a few factors that play into power loss, but the beginning of the domino sequence is high charge air temps. The solution to this is two-fold: a more efficient intercooler, and a tune. While an upgraded 'cooler will help some by keeping charge temps down, should they rise to the stock tune limits (which is easy), the car will still dump power.

In other words, the only thing wrong with your car is that it's stock.

 

[DukesFist]

The issue is heat soak. There are a few factors that play into power loss, but the beginning of the domino sequence is high charge air temps. The solution to this is two-fold: a more efficient intercooler, and a tune. While an upgraded 'cooler will help some by keeping charge temps down, should they rise to the stock tune limits (which is easy), the car will still dump power.

In other words, the only thing wrong with your car is that it's stock.

This actually makes sense because, as I stated, it seems like as I get into my drive home the car actually runs better and doesn't fall on it's face. So instead of a cold car needing to warm up this is a hot car that needs to cool down by way of getting air into the intercooler. I have had some hot rod N/A cars before but never messed with any FI of any type so there is a learning curve.

 

[DukesFist]

So I left work today, 105 degrees on the display, Windows down and A/C off and had no problems. I think my biggest problem is not realizing how much power the A/C robs from this little engine. I am used to driving Mustangs and you really can't tell when the air is on. Just glad I know what to do now and I am looking into tunes so maybe that will help.
Thanks for the help.