sputtering on acceleration F250

[fishin force]

Hoping one of you here know what is going on. It is 2005-06 f250, very low hours. Upon rapid acceleration it will act like it is starving for fuel. It will remain sputtering so to speak until I pull back off the throttle. Then when I go back slowly it will go up on plane with no issues most of the time. If we slow down to ***** then go back up on plane it will do the same thing, sometimes. (When leaving the dock and idling to the channel , about 300 yds it will do it just about every time. It has been going on all last summer So a few tanks of gas have gone through it. These are the things I have done already-changed fuel filter, ran a gallon of seafoam directly through the engine while running.WOT, changed all the little plastic internal screens, pulled the rails and injectors cleaned the injectors the correct way all injectors worked and after cleaning were spraying great, pulled fuel bowl , no dirt or water was in the bowl. checked all spark plugs. replaced primer bulb.

One thing I have noticed, ever since we have owned the boat, and we bought it new, the primer bulb will not pump up hard, I have changed bulbs four times now and still the same thing (Is this a clue? I know I haven't gotten 4 bad bulbs in a row!!) The hours of research I have googled really has not come up with the exact issue and fix. I did find a couple threads on the same issue but they were different year motors and not the same hp. There also no true fixes just shots in the dark and all pointing to the same things I have done. There has been one thing listed , but with argument. The fuel pressure regulator. Most argue that yammie regulators do not go bad, and a couple posters (other sites) that claim to be cert mechanics argue the same point, but they didn't have a solution either. That stupid little $25 regulator cost almost $300, way to much for a guess fix. Anyone ever had the same issue? Or know of a fix. Man I would appreciate it!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

need to add-used it for tubing a couple times last year. I try to throw my son and daughter off, so it is run probably a bit harder than I should, And absolutely not one hic up. So that rulled out float in bowl bad, or fuel line pinching somewhere/

[DennisG01]

Have you tried running with the fuel fill cap removed? If you have a restriction in the vent line (dip in line, bug nest/wax buildup in vent, etc) this is a sure fire way to find out if that's what is causing the issue. If it solves the problem - good. If it doesn't, then the vent line isn't the problem and move on to the next possibility. You don't mention the age of the boat, but another possibility is any/all of the fuel lines are failing internally. Partially blocked pickup... ASV... a couple more possible things that could cause the issue.

A good, quick way to eliminate everything on the boat side of things is to run with a portable tank. Plumb it as close to the engine as you can. If you still have an issue, the problem is on the engine side. If it goes away, the issue is on the boat side.

[rodbolt17]

do you understand what the VST is for?
do you understand how the low pressure pump works below 1200 RPM?
do you understand why there is a relief valve between the VST inlet and the lift pump intake?
I have seen a few regulators rust through but have never seen one fail.
next time you idle out just before racking the throttle have someone pump up the primer bulb.
almost sounds like the VST is running low on fuel.

[fishin force]

Yes we have taken the tank out of the equation ..

the VST going low has been a thought . Why will it only do it after a shutdown then restart? I did not remove the float and that could be it that there is something weird going on with a piece of dirt or something that I missed when I tore it down last fall. If the pumps were failing how would it run all year with only acting up after a shutdown? The research I have done on the prv says the exact thing you did. The cost of that is about a tankful of gas. Lol

[99yam40]

Think about what could cause the motor to not keep the VST full while idling, and then chase those things.
does the lift pump run when needed to keep the VST full?
could the float stick?
could a check valve or recirculation valve be a problem?

seems like there was some other others having this type of problem with no final report on if they cured it

[99yam40]

I forgot lift pump sucking air instead of all fuel might be a problem also

[pstephens46]

I don’t see anything in first post about only occurring after shutdown.

[99yam40]

Yes we have taken the tank out of the equation ..

the VST going low has been a thought . Why will it only do it after a shutdown then restart? I did not remove the float and that could be it that there is something weird going on with a piece of dirt or something that I missed when I tore it down last fall. If the pumps were failing how would it run all year with only acting up after a shutdown? The research I have done on the prv says the exact thing you did. The cost of that is about a tankful of gas. Lol

If that is the only time , maybe heat boiling gas in VST could have something to do with it happening

[99yam40]

If that is the only time , maybe heat boiling gas in VST could have something to do with it happening

But then while idling the lift pump should be filling the VST

[walleye1]

But then while idling the lift pump should be filling the VST

If it getting enough volume of fuel.