2006 Ford Expedition, sluggish mid range acceleration

[David Kuchler]

drive by wire has been a concern in the back of my head, this morning up to temp, i rolled into throttle it went back into first and accelerated very hard, but i never hit the floor with the gas pedal, almost like if i had hit the floor the positioning between throttle pedal and actual throttle housing would go out of sync
ive watched fuel pressure, it seems to hold very steady right at 39 lbs no matter what rpm or throttle position.
And even hot, one time it will accelerate normal and next time fall flat, low throttle input or to the floor matters not. Yesterday going home, grandma style, it went into second, and flat stopped accelerating, i went almost to half throttle to get any additional speed out of the vehicle. (temp gauge and obd say holding steady at 190 water temp)
I have a nice obd reader, but dont honestly know what a good base line looks like, with minimal time watching it with this vehicle. (or any other for that matter)

 

[David Kuchler]

Fly by wire has been in the back of my head for some time now. Seems the gas pedal and the throttle plate aren't running true to each other on bottom end and again on top end, no throttle, full throttle.
This morning i rolled into throttle it went back into first gear and accelerated hard all the way through rpm range, it was at temperature, i never hit full throttle, if i had hit full throttle i dont know it wouldnt have fallen on its face mid range. next light throttle up on green like grandma, and it goes into second at 10 mph, and absolutely stops accelerating, i had to go to near half throttle before it began to accelerate.
Next light it runs perfect again, and or is flat as a pancake again, all while at temp. OBD reader indicated water temp is consistently 190.
Fuel Pressure seems to hold very steady at 39 lbs no throttle full throttle idling or at rpms.
I have a nice OBD reader, but i have no true baseline to match current reading to, is there a place that one could get baseline #'s to compare with while driving?

 

[Bain64]

Sorry I'm just taking a stab in the dark here, but have you tested the throttle position sensor? If you have an OBD reader that logs or graphs, its a simple test. Key On, Engine Off: Watch TPS values and slowly press the gas pedal looking for drops or spikes in the TPS sensor readings. Free and easy check!

 

[stamp11127]

You should be able to see the commanded input from the tps. There is a Ford tech on YT that has good vids on the DBW TB.

They are linked in this thread:
https://www.expeditionforum.com/threads/electronic-throttle-body.36666/