My truck does this same thing when high idle is switched on; however, I have not experienced this any other time. Because you say the behavior is identical, it might be worth disconnecting the high idle switch and trying it again. If you have it wired to an on/off switch like the upfitters I cannot see it making a difference, but I would at least try disconnecting it.

 

May very well do just that!!! Thanks

 

Mine does this as well occasionally. When it does bog, once the RPMs reach the SEIC speed it will also not run smoothly and shakes the entire truck. That'll last between 1-2 minutes and then it smooth's out. Two or three times that I can remember I have quickly stopped it because the shaking is outside of my comfort zone and I'm concerned the engine wants to break something important but nothing bad has ever happened.
There is a higher chance of this occurring when the engine is warm and is typically fine if the engine is cold. It's good to hear others do this as well.


Also, I do need to point out I am not fooled by the RPMs dropping to base idle after activating SEIC when cold since warmup strategy already had the RPMs increased. SEIC is designed to begin at base idle when activated. The bog/shake is an entirely different sound and feel. Hard to explain in a short amount of words!

 

Even when fully warmed, my truck will "die" just for half a second when the high idle is flipped on...just like the OP described, like reversing a boat motor or hitting reverse on a modern 2-stroke snowmobile. It seems like it is programmed to do that then, but shouldn't do it during normal op as the OP describes.

 

It could be as simple as the computer saying "whoa, you can't have that much torque at this slow speed going uphill with that much weight. My calculations are telling me you should be going 25mph based on the throttle input and gear, I've got to back you down a bit or the drive shaft might twist"

 

Still "stumbling" or "bucking" around 1100 RPMs occasionally. Especially when hooked to the 5er. Here is where I caught it on video. Still unable to reproduce to dealer.

 

Well, the last update from Ford did not cure the stumble. The truck dis it multiple times starting off while on our trip this weekend. Wouldn't you know it, the bumper to bumper expired on the 3rd!

 

A continuing problem should be covered. You need to get a hold of ford cust svc and open a case.


Have all of your invoices ready to reference.

 

Here to help, golfmedik! Please send me a PM with your name, phone number, VIN, mileage, and servicing dealer. Have you contacted the dealer yet about the stumble still being there?

Thanks for suggesting Ford Customer Service, senix!

Rachel

 

Rachel, thank you very much for being here and getting involved!! I've received three calls from your service reps about the truck and getting it into the dealer. It is much appreciated!

At long last I was able to take the F350 to the dealer today with the camper attached. FINALLY got the truck to act up while on the computer, and it did it multiple times! You won't believe what is reportedly causing the "stumble"!!! After he reflashed the truck the last time, the tech asked his tech friends around the area about the weird thing the truck does. They told him to check a certain PID. When he hooked it up and went to that PID, he said "that's totally insane!" The parameter showed "783 Driving Events"!!!!!!!!!! Turns out that the culprit to all of this stumbling is a FAULTY BRAKE SWITCH!!!! The truck thinks that I am trying to power break it at most every stop. When he read that it had recorded it 783 times, he said no damn wonder you are going crazy with the truck!!! So, a new brake switch was ordered. Still a little performance issue with the waste gate solenoid, but that will have to be dealt with after it stops the jerking and stumbling. The tech said that people described it as the truck "jumping" when taking off. We'll let you know if it helps when it is replaced.

 

thats great news Monty!

 

Great news. Isn't it funny how solutions sound so simple and obvious after they've been found? When you think about it, it's like "duh".

 

Glad you were able to get it fixed Monty!

 

Did it have anything to do with the "slope assist"? That applies the brake by itself, if it thinks you are starting on a slope. With a heavy camper, the back might sag enough to think it is always starting on a slope. But I guess they verified the brake switch was bad?

 

I originally told them I thought it had something to do with the HILL ASSIST too. They scanned it's operation earlier, but it apparently is the switch on the back of the pedal that has caused it. I tried to get it to act up on hills the first time I took it in, but it wouldn't do it. So this time, I stayed on level ground until it started acting up and then took it to a long hill and it did it much worse. I even let it roll back after the Hill Assist let go and it still did it. So. I'm for anything to cure this beast of it's ailment.