Gen2 v8 throttle servo operation

[hotrod03lincolnlsV8]

I have owned my v8 since summer of 05 and I have experienced the same intermittent throttle problem. Never was a code set until a few weeks ago- ETC Failsafe Mode was displayed and my thoughts were confirmed. (I pulled over shut off the car, restarted it and it is fine)

The car would "stumble" between 55-65 [its happened maybe 8 times ever] I had replaced the TPS at 75k miles and it improved performance but the stumble still happens and happens even with cruise set. (so i know it is not the pedal sensor)

What is the throttle servo consist of? I only see 2 wires at the connector...I was expecting an encoder somewhere, something for servo position feedback. Can the throttle servo become faulty or develop "bad" spots like the TPS? The only apparent option is to replace the throttle body/servo.

My understanding (and could very well be wrong) is the electronic throttle system is somewhat independant of the fuel delivery- the throttle position sensor is what ties the two systems together. The pedal sensor controls the servo only and the pcm can alter the servo position based on many other factors. (wheel spin, road speed, calculated load, etc)

Any thoughts? I didnt want to order a new 230$ throttle body and not fix the problem.

 

[joegr]

I'd check coils and plugs first. What you describe sounds a lot like a coil starting to fail. The #4 coil or nearby could cause a throttle body code.

 

[Quik LS]

+1
common issue that makes the dealer swap the entire throttlebody trying to fix it - only to find it's a coil.

 

[hotrod03lincolnlsV8]

I thought about that too- I dont have any recorded misfires when looking at the stored data. I also took the car to a dealer to have the repair campaign work done. They changed the valve cover gasket sets and 2 coils along the associated plugs.

I have the freeze frame stored and the associated code related to ETC Failsafe Mode - Limited power...or something to that effect [im across the country for work at the moment]

I have changed the plugs at 50k and with 78k on it now- I have done the work myself (except the warranty stuff) I am out of ideas as to the cause...

Sorry i didnt throw this in the first post- i was trying to keep it short.

Thanks guys!

 

[owlman]

It's probably one of the 6 coils you didn't replace

 

[hotrod03lincolnlsV8]

lomao ....i wish it were that easy!!

I have changed 2 coil packs and 2 more under warranty with the gaskets. no misfires, new plugs, no vac leaks...im out of ideas. I was completely stumped until the electronic throttle control failsafe message appeared- this is the only clue ive got.