At approx. 12000 miles, in cruise 2005 F150 Lariat began to shake with low RPM. All engine indications were normal. After approx. 5 mins., I had accelerater to floor board and the truck would only move less than 5mph. Dealership picked it up roadside. They have now changed out a coil, all injectors and are still scratching their heads. An engineer at Forn thinks it may be bad gas. Anyone else experiencing this problem?

 

sounds like bad gas to me have they flushed the fuel system and tank and put fresh gas in?

 

Your truck has ETC (electronic throttle control).
Flooring it and not going anywhere suggest to me there is a fault in that system.
I cannot believe dealer service would chase injectors, coils etc for this type problem.