2020 Limited Almost No Acceleration when Cold

[Lghtspeedz]

Hi Everyone,
I have a 2020 Limited 4x4 sitting right at 62,500 miles. Over the past few months the truck has developed this strange issue. It only happens after the car has sat for a while. The shortest time frame I have noticed it is four hours. I get in the car, start it up, usually idle for 5-20 seconds while I get everything situated (buckle up kids, etc.), then head out. Sometimes I'll do a reverse before putting it in Drive. Other times I am pulling straight forward. The car will move forward and I will hit the accelerator but it just starts to move very slowly. I have watched the turbo gauge and the gauge moves but the car doesn't really accelerate all that much. Anywhere from 5-20 seconds later the power will all of a sudden surge. It's not smooth and almost a bit jerky. Sometimes if I'm turning during this period I swear I hear a grinding or resistance noise at takeoff. I can't pinpoint it and it's very subtle.

Any thoughts on what this is? I'm struggling with how I'll even direct the shop to look at this. Oddly enough, I had just started looking at ordering a '24 to get the last of this model. I like this generation a lot and don't love the screens I've seen on prototype 2025's.

Thanks for any insight!

 

[Hellwig]

Apparently, it is a transmission issue.

 

[TheDoug]

I have this issue as well... almost feels like you are being held back by something and then all of sudden its fine. I also think its a transmission issue.

For me, I start the car and pull out of garage (i back in so just pull straight out) and then it will take from my garage to about my first left turn which is about a block and then its fine the rest of the time. There are some days I remote start and let it sit for a few minutes and it drives fine.

Quality is job 1

 

[2020-MAX-Limited]

Yea, there's a delay when putting in D. I usually wait until I feel the tranny engage (the engine RPM drops slightly) before hitting the gas pedal. I don't expect this heavy truck to respond like a sports car, so I'm just patient with it.

 

[Mr Big]

When you are accelerating, is the rpm going up drastically or just no power like a dragging E-brake?
I ask because it's one thing if the tranny is slipping and another if it is not? Very well may be sensor tied to temperature, as when it warms up the symptom is gone.
I found this list: COMMON CAUSES OF POOR ACCELERATION
I have an EV that will not move until the key is on for 30 seconds in warm weather and 3 minutes in cold weather. I have not been able to pinpoint it, but am sure something has to warm up to make a connection. So, to me your issue sounds like something, (a sensor connection) has to get warm before making contact. But I could be way off base as well.

 

[Lghtspeedz]

I have this issue as well... almost feels like you are being held back by something and then all of sudden its fine. I also think its a transmission issue.

For me, I start the car and pull out of garage (i back in so just pull straight out) and then it will take from my garage to about my first left turn which is about a block and then its fine the rest of the time. There are some days I remote start and let it sit for a few minutes and it drives fine.

Quality is job 1

This is exactly what I experience. I tried remote starting the car this morning for about 30 seconds and it seemed to be better. The truck behaved better the whole morning if driving around too. Very interesting.

Yea, there's a delay when putting in D. I usually wait until I feel the tranny engage (the engine RPM drops slightly) before hitting the gas pedal. I don't expect this heavy truck to respond like a sports car, so I'm just patient with it.

Yes, I’ve learned to time that shift delay. In this case it’s once you’re actually driving.

When you are accelerating, is the rpm going up drastically or just no power like a dragging E-brake?
I ask because it's one thing if the tranny is slipping and another if it is not? Very well may be sensor tied to temperature, as when it warms up the symptom is gone.
I found this list: COMMON CAUSES OF POOR ACCELERATION
I have an EV that will not move until the key is on for 30 seconds in warm weather and 3 minutes in cold weather. I have not been able to pinpoint it, but am sure something has to warm up to make a connection. So, to me your issue sounds like something, (a sensor connection) has to get warm before making contact. But I could be way off base as well.

I get what you are saying. The RPM’s don’t shoot up like the transmission is slipping. It’s like the car has no power and it just accelerates really slowly. Like TheDoug said, maybe 10-30 seconds later it just surges and all the power comes back. I’m just not even sure how to have it diagnosed. I’ll have to bring the car in overnight (inconvenient) and hope they diagnose it on the first shot in the morning. I was hoping I could pinpoint the issue and tell them what the problem is.

 

[Alwaysthinkin]

Have any of you tried using Sport setting? I ask because I used to have a hesitation which seems to be gone since I started using Sport mode pretty regularly. Also, do you have the visual on dash showing which gear you are in when these hesitations happen?

 

[duneslider]

I haven't noticed this in my expedition but in my jeep after it sits the fluid drains out of the torque converter and fluid isn't pumped when in park, so even sitting and idling the torque converter isn't filled. So, when I put it in drive or reverse it takes a little bit for the fluid to get pumped around before it will drive. I don't know why it does this on my jeep but its been doing it for a long freaking time and nothing else is wrong. The jeep has 230k miles and has probably been doing this for at least half that time or more.

I am not an auto transmission expert but I suspect there is some sort of anti-drain back that isn't working. In the nearly 18 years I have had my jeep and been on forums nobody has ever said this issue with the jeeps is an issue to be worried about. Not sure if that is the case with this ford transmission or not.

 

[bmpcamry09]

Lots of speculation here from other posters but none of these answers are actually helping you.

From my testing of tunes and data logging over the years, I got curious as to what caused this and figured it out.

There is nothing wrong with your vehicle. What you are feeling is the engine going from what is essentially warm up mode to normal operation mode. All gen 2 ecoboosts do it, some are more noticeable than others. More noticeable when vehicle has sat for long periods and in cold weather.

When you first start your vehicle cold, it relays on solely the direct injectors to fuel the engine instead of an DI/PI split like during normal warm operation. This cold start mode essentially floods the engine with rich amounts of fuel. The high pressure fuel pump is activated and is doing all the fuel flow in this mode, which can be easily heard with the engine cover off. Combined with heavily retarded ignition timing (usually -5 to -20), this heats up the catalytic converters quickly. On most Expeditions, this mode will stay engaged until the coolant temp hits about 111 degrees. There is a very audible change in the engine when this mode shuts off that can be easily heard with the hood open after cold start. This is a strategy that newer direct injected vehicles use to help the engines warm up faster and to keep the EPA happy.

If you drive off when the engine is still in this warm up mode, it will feel very very sluggish until it clicks out of that mode. The retarded ignition timing and rich fueling strategy is causing the bog that you feel. The sudden surge and change in the way the engine sounds you are experiencing is the cylinder head temperatures reaching the threshold of the engine going into normal operation, which at lower RPM, is port injection with the high pressure fuel pump deactivated. The louder turbo noises you are hearing at the same time are because the engine is having to force more volume of air into the engine during the warm up mode due to the extra rich fuel settings while in said mode.

Hope this helps. I am not sure anyone has actually explained this on this forum or not so hope this helps people. There is a excellent detailed NHTSA article on the 2017 F150 3.5 ecoboost, which was the first year for the gen 2 (which started in 2018 for the Expyy), that dives into all these details as well.

Drove me crazy too until I dove into it. I actually built a custom tune one time that disabled this cold start feature to confirm my findings. Don’t waste your money or stress over it. It’s normal!

If you have access to Forscan or a quality scan tool, watch the spark advance PID during your cold start and you should see a direct correlation between the sensation and spark advance when the engine comes out of cold start mode. Timing will instantly go positive or over 0, your HPFP will shut off, and it’ll feel normal.

 

[5280tunage]

Lots of speculation here from other posters but none of these answers are actually helping you.

From my testing of tunes and data logging over the years, I got curious as to what caused this and figured it out.

There is nothing wrong with your vehicle. What you are feeling is the engine going from what is essentially warm up mode to normal operation mode. All gen 2 ecoboosts do it, some are more noticeable than others. More noticeable when vehicle has sat for long periods and in cold weather.

When you first start your vehicle cold, it relays on solely the direct injectors to fuel the engine instead of an DI/PI split like during normal warm operation. This cold start mode essentially floods the engine with rich amounts of fuel. The high pressure fuel pump is activated and is doing all the fuel flow in this mode, which can be easily heard with the engine cover off. Combined with heavily retarded ignition timing (usually -5 to -20), this heats up the catalytic converters quickly. On most Expeditions, this mode will stay engaged until the coolant temp hits about 111 degrees. There is a very audible change in the engine when this mode shuts off that can be easily heard with the hood open after cold start.

If you drive off when the engine is still in this warm up mode, it will feel very very sluggish until it clicks out of that mode. The retarded ignition timing and rich fueling strategy is causing the bog that you feel. The sudden surge and change in the way the engine sounds you are experiencing is the cylinder head temperatures reaching the threshold of the engine going into normal operation, which at lower RPM, is port injection with the high pressure fuel pump deactivated. The louder turbo noises you are hearing at the same time are because the engine is having to force more volume of air into the engine during the warm up mode due to the extra rich fuel settings while in said mode.

Hope this helps. I am not sure anyone has actually explained this on this forum or not so hope this helps people. There is a excellent detailed NHTSA article on the 2017 F150 3.5 ecoboost, which was the first year for the gen 2 (which started in 2018 for the Expyy), that dives into all these details as well.

Drove me crazy too until I dove into it. I actually built a custom tune one time that disabled this cold start feature to confirm my findings. Don’t waste your money or stress over it. It’s normal!

Super cool response, thanks for this.