Acceleration Problem

[MCExpy10]

I was doing some searching around on the forums here and think I may have a few of the common problems our trucks have. I've been fighting with the dealership on this since we bought it (we have an extended warranty). It's a 2010 with 105,000 miles on it.

When sitting at a stoplight, you can feel the uneven motor vibrations through the car as your sitting. I think it might be a bad motor mount.

If you're at cruising speed on the freeway and you go to pass (and put your foot all the way down on the accelerator) it takes probably 3-4 full seconds to downshift and apply power. I asked about this a while back and the agreement on the forums here was to gradually put your foot down and it would start downshifting as I put my foot to the floor. That definitely helps. Cuts about a second off.

I think this is also related, under full acceleration from a dead stop, a few of the gear changes bring the truck up to "redline" and it seems like a fuel cut-off. I'm not really sure what redline is on the truck because the gauge doesn't have any markings. I assume 6500? So I'll be fully accelerating being pushed into the back of my seat, then it seems like it fuel cuts and pushes me forward (almost as if someone were to tap the brakes relatively hard), then it shifts and repeats. LOL!

I really do like this truck, but I feel like it's going to take me to the cleaners after the warranty is up... Tows like a dream though, which is why we bought it.

 

[rollavvti06]

Tranny fluid been changed ever?

 

[TobyU]

Isn't that a drive by wire with a electronic throttle control? GMs mess up a lot but do almost always pop a code. Sounds like that or TPS which is often built onto electronic ones is got a dead or flat spot.

 

[chuck s]

All 3d Gen Expeditions are DBW. Since 2007.

-- Chuck

 

[bobmbx]

I was doing some searching around on the forums here and think I may have a few of the common problems our trucks have. I've been fighting with the dealership on this since we bought it (we have an extended warranty). It's a 2010 with 105,000 miles on it.

When sitting at a stoplight, you can feel the uneven motor vibrations through the car as your sitting. I think it might be a bad motor mount.

If you're at cruising speed on the freeway and you go to pass (and put your foot all the way down on the accelerator) it takes probably 3-4 full seconds to downshift and apply power. I asked about this a while back and the agreement on the forums here was to gradually put your foot down and it would start downshifting as I put my foot to the floor. That definitely helps. Cuts about a second off.

I think this is also related, under full acceleration from a dead stop, a few of the gear changes bring the truck up to "redline" and it seems like a fuel cut-off. I'm not really sure what redline is on the truck because the gauge doesn't have any markings. I assume 6500? So I'll be fully accelerating being pushed into the back of my seat, then it seems like it fuel cuts and pushes me forward (almost as if someone were to tap the brakes relatively hard), then it shifts and repeats. LOL!

I really do like this truck, but I feel like it's going to take me to the cleaners after the warranty is up... Tows like a dream though, which is why we bought it.

Completely reset the PCM. That will 'unlearn' the shift points and throttle maps from the previous owner. The following will help in diagnosing any issues by resetting the computer to 'default' values.

Instructions to clear and then calibrate are here:

 

[rollavvti06]

Completely reset the PCM. That will 'unlearn' the shift points and throttle maps from the previous owner. The following will help in diagnosing any issues by resetting the computer to 'default' values.

Instructions to clear and then calibrate are here:

I did that on my f150 and it fixed my shifting issues...

 

[TobyU]

All 3d Gen Expeditions are DBW. Since 2007.

-- Chuck

I should have guessed that since The Navigators were 03-06 fit second-generation in 07 start of the new ones. I guess the Expeditions followed the same.
Ford had that crazy thing back when the new F-150 and 250 came out that the 350 didn't come out with a new style to a couple years later.
That throttle problem sounds just like what the GM throttle bodies do when they get a flat spot. I haven't had anything 07 and up for Ford. I'm staying far away from the three valves and VCT for as long as I possibly can.

 

[MCExpy10]

Hey everyone, thanks for the replies! Sorry for the delayed response. My car is DBW. I've been told multiple times that the sluggishness of the transmission is due to my year being the first year of the drive-by-wire. Sounds like BS to me.

I might as well start with the free/cheap stuff first. It's worth noting that I have not had the transmission fluid changed. I plan on making an appointment for a transmission shop to do this and the differentials. Whatever the 100,000 mile service entails. No check engine lights in the duration I've had it (roughly 3 years, and 30,000 miles).

Problem now is that most dealerships are just parts swappers now. At least what I've dealt with so far with this thing. If the check engine light isn't on, everything is A-OK... I have an extended warranty (with a $250 deductible), but that expires in March so I'm trying to get my money's worth out of it before I'm on the hook for everything.

 

[MCExpy10]

It's also worth noting that I'm getting atrocious gas mileage. Even for our truck's already low standards. I do mostly commuting traffic, not really stop and go. I'm at a hair above 12MPG. Granted we've had a lot of weather changes around here. Not to mention winter gas.

Planning on running through this test on the TPS tomorrow, and will also try and reset my PCM.
https://easyautodiagnostics.com/ford/4.6L-5.4L/tps-diagnostic-tests-1

 

[JExpedition07]

If you can feel heavy vibrations at idle it’s possible you have a misfire. They often don’t set of a CEL. At your mileage it’s worth asking because they are due. Have spark plugs and boots been changed? Both items can cause misfires at the 100k mark and cause acceleration concerns. The drive by wire can be sluggish at times on the Expeditions but it’s not because your model year. Drive by wire has been in the Expedition since the 2nd gen starting in the 2004 timeframe.

 

[MCExpy10]

If you can feel heavy vibrations at idle it’s possible you have a misfire. They often don’t set of a CEL. At your mileage it’s worth asking because they are due. Have spark plugs and boots been changed? Both items can cause misfires at the 100k mark and cause acceleration concerns. The drive by wire can be sluggish at times on the Expeditions but it’s not because your model year. Drive by wire has been in the Expedition since the 2nd gen starting in the 2004 timeframe.

Thanks, that's excellent info! Plugs and boots have been done, shortly after I bought it at 80,000 miles. They ended up warrantying one of the spark plugs out for a mis-fire.

 

[1955moose]

Before changing out any parts, run an advanced diagnostic either by you or a shop. You want to check fuel trims, kv readings of plugs/coils, etc. I think your problems a little more than a fly by wire problem. It's even possible you may have an internal motor problem. Let us know what fixes it, it will help others.

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[TobyU]

Before changing out any parts, run an advanced diagnostic either by you or a shop. You want to check fuel trims, kv readings of plugs/coils, etc. I think your problems a little more than a fly by wire problem. It's even possible you may have an internal motor problem. Let us know what fixes it, it will help others.

Sent from my N9131 using Tapatalk

Sounds like throttle body motor to me. Sometimes a good check engine light reset and battery disconnect reset like in the video can help for a long while.

Also, turn key to on but not running and push pedal to floor fast and hard a number of times and hold it there for a bout 3 seconds a number or times too.

These things are like little volume controls with multiple little copper fingers sweeping over the wiring to chance resistance to tell throttle where to go.
They get flat spots and damaged fingers and can get corrosion etc.

 

[2010ELExpy4x4]

Ours had the terrible lag also. This is our first DBW, took me by surprise when I was trying to get on the I5 and a fast moving big rig was approaching I mashed the peddle and nothing, for what seemed like an eternity.
That experience started my research in to the issue, there seems to be many contributing factors i.e. traction control etc.
Ultimately I bought a Superchips programmer, made a huge difference all around, increased throttle response, better shifting, and mileage increased, also I was able to program for the larger tires.
Superchips also sells a stand alone throttle response module, and doesn't need the programmer, but the programmer offers more options.
As far as the uneven vibrations ours does it occasionally, haven't figured it out yet.
Do check the tranny fluid, ours had a bulkhead connector leak, had to drop the pan to replace, noticed quite a difference with new fluid even before using the programmer.

 

[MCExpy10]

Ours had the terrible lag also. This is our first DBW, took me by surprise when I was trying to get on the I5 and a fast moving big rig was approaching I mashed the peddle and nothing, for what seemed like an eternity.
That experience started my research in to the issue, there seems to be many contributing factors i.e. traction control etc.
Ultimately I bought a Superchips programmer, made a huge difference all around, increased throttle response, better shifting, and mileage increased, also I was able to program for the larger tires.
Superchips also sells a stand alone throttle response module, and doesn't need the programmer, but the programmer offers more options.
As far as the uneven vibrations ours does it occasionally, haven't figured it out yet.
Do check the tranny fluid, ours had a bulkhead connector leak, had to drop the pan to replace, noticed quite a difference with new fluid even before using the programmer.

This is good to know. I was also looking at programmers, but wanted to make sure nothing was wrong with it first. It's still under an extended warranty until March. Despite me bringing it in a number of times since owning for this issue, I'm told it's normal...

I had the fluids changed out yesterday, and it does seem to perform slightly better.

I totally associate with you on the pedal mashing. LOL! Like I said, I can usually count to 3 before it actually applies some power to the wheels. I still think I have a bad COP, but the dealership says otherwise. I'm just annoyed that they basically don't do anything unless the check engine light is on. Nobody looks at trims, voltages, etc. Just swapping parts now it seems like. I can do that! I mean it's not like the job is any easier for me to pay someone to do it.

Sorry, just frustrated. I have an old OBD2 scanner that I'm going to try and get going on a laptop and see if I can grab some readings just to make sure everything is working proper. When I was womping on it last night, it didn't seem to go up and do that fuel cut thing anymore. Time will tell though.

 

[1955moose]

Most but not all dealers train their people on one thing, sell cars, sell service. Your dealer is taking it to an extreme. I can't believe the part of waiting for a CEL to come on. Get ahold of the Ford regional service rep, and explain your situation. Last thing any dealer wants is to waste time/money in a court battle. Film, and audio, everytime this happens. If you have another dealer fairly close try them first. My sister in law had trouble back in the eighties with a 3.8 Oldsmobile. The dealer here in DalyCity, couldn't or wouldn't fix the famous pinging problem. She got ahold of the Rep, brought it to a Burlingame dealer, and they found a bad sensor. She said the difference was huge after.

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[Adieu]

It's also worth noting that I'm getting atrocious gas mileage. Even for our truck's already low standards. I do mostly commuting traffic, not really stop and go. I'm at a hair above 12MPG. Granted we've had a lot of weather changes around here. Not to mention winter gas.

Planning on running through this test on the TPS tomorrow, and will also try and reset my PCM.
https://easyautodiagnostics.com/ford/4.6L-5.4L/tps-diagnostic-tests-1

12mpg city is normal-ish if 4x4 and 3 rows, especially if EL or you carry cargo or people or have LT or AT tires...

If that's highway or a 4x2 swb, then that's kinda low....then again, the redline thing is weird, 5.4's are pretty peppy for a big truck, and typical driving RPMs are 1500-2000 not 6000


Misfire...hmmm...you didnt wash your motor with a garden hose did you (DON'T)? Check for coolant leaks into spark plug wells (that crap does NOT evaporate and will kill your coils), also check operating temps and coolant condition, might need clean coolant and a new tstat to run at optimal temps (middle of the gauge, maybe slightly past middle)

 

[1955moose]

Funny you said that about the temp running in the middle. I put in a new alternator in my 2000, about a month back. I had to lift up the upper hose to get alt in and out. Since doing that my gauge reads a little cooler. Disrupted something by doing that. Runs fine, and heaters still ok.

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[Adieu]

Funny you said that about the temp running in the middle. I put in a new alternator in my 2000, about a month back. I had to lift up the upper hose to get alt in and out. Since doing that my gauge reads a little cooler. Disrupted something by doing that. Runs fine, and heaters still ok.

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Prolly dislodged a blockage of gunk lol....with new tstat, new coolant, new heater hoses, new plugs, new cops, post-backflush, my SSV ran at like 55% on the gauge. Then again, that's with like 185k mi on motor so who knows

 

[1955moose]

I would have thought by bending that hose, I'd go higher, not lower. Anyhoo all is well cooling, and running, so just keep an eye out.

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