Something is wrong

[Kyle Maguire]

Okay so I just bought a 2010 ST a little over a month ago and I went for a really long drive today around New Mexico. Long straight highway roads just cruising. Out of nowhere my truck was not letting me go over 80. Every time I would give it alittle gas the rpm's would rocket up to 5000 and jump up and down rapidly. When I'm at the stop light, same thing UNLESS I "granny foot" it and barely give it gas. When it does it, it makes my truck jump and lag with the rpm's. Almost as if I'm tapping the gas letting it go quickly, over and over again. Same when I floor it, it like won't shift and stays around the 4000-5000 rmp and constantly fluctuating up and down rpm's. That's the best way I can describe it without sounding kinda dumb. Maybe I still am idk. I just need some help if you guys have any advice. Thank You. My truck has 76000 miles if you need to know.

 

[Steve Krusich]

When was the fuel filter last changed?

 

[Yardsale]

This does not seem like a fuel problem to me.



Seems like either a transmission or engine control problem.



Throttle position sensor?



From where did you purchase - dealer of private party? If from dealer, that's where I'd take it. If from private party (assuming no warranty), do you have any maintenance records?

 

[swshawaii]

First thing to do is check for trouble codes and write down the numbers. Most larger auto parts stores will do it free. Call around. GL

 

[EddieS'04]

Gen 2 Tracs have the motorized TB. I suspect the TB drive motor or something with the TPS or the throttle electronics...

 

[JohnnyB]

Probably the tranny. I had a 2007 ST that the tranny went at 46K miles. It was bucking like a bronco. other times completely normal. The mechanic was about to bring it back to the dealership and say nothing was wrong. Then out of no where he got cut off at a stop sign, hit the brakes then accelerates and it bucks like he had never seen before.

They had my ST for 19 days before I got a "new" certified rebuilt tranny. After that I traded it in later in the year for the 2010 I have now. They gave me a great trade in price too.

 

[Vic Sorlie]

+1 on scanning for codes. The inexpensive scan tools available to us DIYers or at a parts store may not do it for you though. You may have to take it to a Ford dealership shop for thorough diagnosis. If the engine/transmission programs need updating they'd do that at the same time. There's also a chance that it's something as simple as a fuel filter. If you don't know when it was last changed it's inexpensive to have it changed, or more so if you do it yourself.

 

[Todd Z]

Scan for codes, But Either Throttle body is bad or the Tranny is acting up.



Todd Z

 

[Jackson Ellis]

Just thinking out loud here - 2 possible issues. Do you see any lights on the dash coming on when you get these symptoms? Do you have AWD? If you have mismatched tire sizes, it could be confusing the traction control or auto AWD system. You'd see reduced power in some situations, and you might feel the truck trying to buck or decelerate. If your tires are all the same size, close to the same tread wear, and all properly inflated, then I'd try an experiment on the speed sensors by turning traction control COMPLETELY off (long hold the button), and see if the truck will give you full power. Could be a speed sensor with the traction control/ABS system acting up or failing. Turning off the TCS completely will let the engine ignore any sensors telling it to back off.

 

[John Zuber]

What I want to know is why people post what appears to be a serious problem, but yet doesn't post any follow-up information? What's up with that?