05 F250 rpm reduction

[dracer]

Making a long run down the ICW at about 4600 4800 RPM for close to an hour, pull down to no wake zone and go to get back on plane and the motor will not go past 3300 RPM, back to neutral shut the motor off for literally a second start back up and take off with full range of throttle. No overheat alarms and the water out of the motor is normal. Same issues the rest of the trip didn't matter if I was on plane for a minute or an hour when I throttle down and back up the RPM is limited shut off and restart.....runs fine.
I replaced the mid section 2 years ago because of corrosion and just replaced the high pressure fuel pump.

thanks for any help.

[greasyshaft]

Had it connected to YDIS? probably be good to take it to a dealer and get 'em to check her out maybe even sea trial while monitoring on YDIS, there's bound to be something showing.
There's a lot of bits and bobs on that engine that could contribute to the problem, many values are reset when you shut off the engine.
How many hours has the engine done?

[greasyshaft]

Yeah that engine is basically all out computer con*****ed. the F225A is pretty basic in comparison.

[dracer]

Thanks for the help. What is YDS? Motor has 2200 hrs and still strong as ever..... We'll except for this little hickup.

[greasyshaft]

YDIS is the diagnostic system, used on PC

[rodbolt17]

could be as simple as the lift pump relief valve leaking, at low speeds the lift pump cycles at 10 seconds on,20 seconds off.
if that valve leaks the VST fuel level gets low at idle speeds.
could be the accelerator position sensor, could be a lot of things but if it was actually in an RPM limiting status you get alarms also and engine speed is held to about 2500 max.

next time you try it bump the motor up to about 1400 RPM for 30-40 seconds then nail it.
if the issue goes away have a look at that relief valve.