2020 Limited Almost No Acceleration when Cold

[BP 09]

No problem. Just like to get the proper information out there for people! When I got into tuning I learned all kinds of random off the wall stuff about these things and like to share the info.

 

[Lghtspeedz]

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?

I have, though not necessarily in that instance. It's usually in the 1st to 3rd gear jump. It's always low speed. It's usually when I'm first pulling out of the parking lot at work or from the garage in the morning. It's usually very brief.

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.

Thank you so much! This explanation makes a lot of sense, except I'm wondering I'm only noticing this now and not years go. But... maybe my get in and go drive style has changed. I am certainly more on the go than I was. It makes sense and it does feel like the motor is holding back than all of a sudden goes.

I love this truck. It is honestly my favorite car I've ever owned and has been rock solid for the time I've had it. It has the perfect amount of technology and capability. I've been toying around with trying to keep it for a really long time and buying a daily driver or ordering a '24 as close to the way I'd ideally get it (Ford doesn't make one the way I'd want it). I see that you used MPT to tune your car and changed the thermostat. What can you tell me about the tuning? If I keep the car I want to go for a tune to smooth out the transmission a bit. It might be nice to have effortless power if I can keep the reliability. Did you do anything else to mod the car for these tunes? Seems like some guys do other upgrades too. Keep in mind, I know very little about it other than people get good results.

I will say this about the '24 I test drove: it was clear to me that Ford had done a lot to refine the powertrain on the car. The shifts were smooth and the power delivery was top notch. The car felt much lighter and smaller to drive because of it. It also did not skip gears like mind does, which I think really helped. There were a few changes I didn't love but it seemed like they had really dialed in the powertrain.

 

[BP 09]

I have, though not necessarily in that instance. It's usually in the 1st to 3rd gear jump. It's always low speed. It's usually when I'm first pulling out of the parking lot at work or from the garage in the morning. It's usually very brief.

Thank you so much! This explanation makes a lot of sense, except I'm wondering I'm only noticing this now and not years go. But... maybe my get in and go drive style has changed. I am certainly more on the go than I was. It makes sense and it does feel like the motor is holding back than all of a sudden goes.

I love this truck. It is honestly my favorite car I've ever owned and has been rock solid for the time I've had it. It has the perfect amount of technology and capability. I've been toying around with trying to keep it for a really long time and buying a daily driver or ordering a '24 as close to the way I'd ideally get it (Ford doesn't make one the way I'd want it). I see that you used MPT to tune your car and changed the thermostat. What can you tell me about the tuning? If I keep the car I want to go for a tune to smooth out the transmission a bit. It might be nice to have effortless power if I can keep the reliability. Did you do anything else to mod the car for these tunes? Seems like some guys do other upgrades too. Keep in mind, I know very little about it other than people get good results.

I will say this about the '24 I test drove: it was clear to me that Ford had done a lot to refine the powertrain on the car. The shifts were smooth and the power delivery was top notch. The car felt much lighter and smaller to drive because of it. It also did not skip gears like mind does, which I think really helped. There were a few changes I didn't love but it seemed like they had really dialed in the powertrain.

I am a huge supporter of tuning. Professional tuning fixes everything the factory fell short on without sacrificing reliability. Basically all the current tuning companies build reliable tunes especially if you’re just running normal pump gas. A good 91 octane or 93 octane tune will blow you away.

Ford has done away with the 3-5 skip shift in all their newer stuff. Still an occasional 1-3 shift at light throttle on their newer stuff, but for the most part, skip shifting is a thing of the past on their new stuff.

I have used all the big companies with the exception of Livernois. All have pros and cons. ZFG, MPT, Boostking, and Gearhead are my favorite.

Adam at ZFG Racing is probably the most “custom” but he’s also the most expensive. He gives huge power and a snappy transmission. I run a 91 tune from him and I can break under 5 seconds on 0-60 no sweat. He really knows his stuff and keeps things safe.

MPT makes a silky buttery smooth engine and transmission with diesel like power throughout the power band. They work some magic. Hard to explain but their stuff feels a lot different than the others. My MPT tunes lean pretty hard on boost and feel very stout around town. I think they tweak fueling and cam scheduling more than some others. Their customer service is the best in the game by far.

Gearhead makes probably the “safest” tune as he lets his tunes run up more in RPM with less dramatic boost. Matt’s tunes pull extremely hard high in the RPM range. He also allows any octane in all his tuning. His transmission is also very snappy and always in the right gear. His tunes feel a lot like ZFG in a lot of ways. Matt is probably the biggest wealth of knowledge in the ecoboost world and he is very OCD about having a perfect file for you without needing revisions.

Boostking is also great. Very custom and his stuff is very similar to ZFG in feel and how he likes to do multiple revisions until you’re happy. Brett is an instructor for the tuning school and is one of the OG SCT tuners who has mentored a lot of other professionals. Very knowledgeable and very strong tunes.

I am way over the top in checking my stuff to make sure it’s healthy and I have thoroughly logged all 4 and have complete faith in all 4 companies and can vouch that they are all safe.

5 Star is talked about a lot, but overrated in my opinion. I am not a fan of how they manage temperature protection and LSPI tables. Their transmission tuning really only touches shift scheduling and torque converter settings but they don’t dig deep into the trans to make improvements like the others do. Their tow files feel good with a trailer hooked up, but their stuff doesn’t feel nearly as refined as the other 4.

Just take about $1200 from the coffee can. Get an intercooler, a 170 thermostat, and a tune from any of the 4 I mentioned, and you’ll fall in love again and won’t want a 24.

 

[BP 09]

As far as my engine mods go, I run 91 and 93 octane tunes from those companies, usually just ZFG and MPT. I also have the 170 thermostat, CVF Titan v2 intercooler, step colder spark plugs, grill shutters deleted and engine cover removed. The summers in my area are 100 plus and I tow. With shutters removed, engine cover off, and the intercooler, I never see over 200 degrees coolant or trans temps now.

Other stuff is Bilstein 5100 suspension all the way around, and upgraded LT tires. All combined made my Expy perfect for what I want and need it for.