Raptor won't stay at 10-15 mph speed after start.

[SlasherMcGee]

Update: I found the following TSB for 5.0 engines. Word on the street is the same issue in the TSB occurs for many different ford vehicles.

http://api.viglink.com/api/click?fo...13-01-10.pdf&jsonp=vglnk_jsonp_13681434915319

I also did a test tonight where I let the pickup run for about 4 minutes before driving and could not reproduce the issue. I forwarded the TSB on to my dealer. Maybe they can find something for the 6.2 engine. I'll update this thread with my findings.

This was also fixed on the 5.4:

http://www.fordraptorforum.com/f183/tsb-10-24-1-5-4l-surge-when-cold-13654/





I've got a weird issue on my brand new raptor...

1. Start engine after it's been sitting for some time...
2. Accelerate slowly to 10 MPH. Keep gas pedal at this same position throughout the next steps.
3. You will see the RPM and speed drop within a few seconds.
4. After a few seconds RPM and speed will spike back to 10 mph, jerking the vehicle forward. It might actually spike to 15-20 mph very rapidly.
5. The RPM and Speed drop again as if you aren't touching the gas.
6. RPM/speed will increase again, jerking the vehicle to 15-20 mph
7. This could continue for some time... 3-4 “Jerks” is possible or more…Sometimes it’s only once..

*Issue only seems to occur at very low speeds… 10-15 MPH or less.
*Issue always occurs in the morning when leaving house.
*Issue always occurs when leaving work later in the day.
*Issue does not appear "as bad" when vehicle has been recently driven.
*After you've accelerated to 20-30 MPH for a bit and then try to reproduce the issue by dropping speed back to 10-15 MPH, issue won't repro.... As in you can hold the gas pedal at a certain value and the pickup will stay at 10 mph with no jerking.
*I’ve been able to reproduce the problem with the transmission in 1st(bottom position on gear shift).

 

[Cummins_Bred]

Throttle position sensor? Sticky throttle body?

 

[SlasherMcGee]

Throttle position sensor? Sticky throttle body?

That was/is my assumption.. Something throttle specific. But what's weird is that if I rev it up numerous times before I take off while in park(which you would think that would "free up" any stuck throttle body) it has no effect. Also you'd think the throttle position sensor would "stay bad" rather than starting to work correctly after driving for a bit. But I might be wrong...

 

[Fred]

How new...might just need to drive it...since it gets better with use...otherwise don't hesitate to take it Tao a dealer...

 

[SlasherMcGee]

How new...might just need to drive it...since it gets better with use...otherwise don't hesitate to take it Tao a dealer...

I've got 250 miles on it right now.. started noticing it after about 100 miles.

I took it to the dealer last night and they said to bring it back on Tuesday and they'll look further but it was probably just going to need a "Reprogramming" of the adaptable transmission... This was my thought right away as well, but I've had no issues with "hard shifting".

I called my salesman today to say I need this looked at now rather than later. I can't take a chance that I'm causing damage to a $50,00 truck. One of the service guys called me back and after I explained the issue he said they recently sold an F150 Harley edition to a guy who is complaining about the same issue. They are looking into the problem now but they have no clue what's causing it.

 

[shooterAMG]

Sounds like the programming the ECU/PCM is using during the Open Loop phase is way off. It's trying to dump fuel in and it's choking it. Maybe the default settings for the oxygen levels is off causing the excess fuel.


Or I could be a million miles off. Hope dealer figures it out. You never want a new truck to barf like that.

 

[SlasherMcGee]

Sounds like the programming the ECU/PCM is using during the Open Loop phase is way off. It's trying to dump fuel in and it's choking it. Maybe the default settings for the oxygen levels is off causing the excess fuel.


Or I could be a million miles off. Hope dealer figures it out. You never want a new truck to barf like that.

I am really hoping it's just a simple programming issue...

 

[Fred]

Your engine wants to be powerful and efficient. Clog it up, and don't let the waste (exhaust) out, leave the exhaust to just putt-putt on out of there, and you lose power and efficiency. Your oxygen sensors will always read wrong because of the contamination of the backing up exhaust, and so the engine will always think the fuel flow is wrong, and will keep dumping fuel...

 

[CAbimmer]

Mine does this when is cold, I think it has to do with the lockup on the Torque converter.

 

[Fred]

It is in open loop when cold...ECM does not rely on O2 sensors in open loop but are required to run in closed loop...