Merc EFI Four Stroke 115 stalling after throttling down

[Whatever1969]

I am working on a 115 four stroke that is having some hesitation when throttling up and wants to stall when throttling quickly back to idle. I hesitate to mention that this motor took water into the fuel a year and a half ago. The fuel line fell off and into the motor well, which was full of water. Therefore it aspirated pure river water until it stalled. We removed the water and got the motor running again. It was running quite rough for a while until I flushed the fuel system and ran seafoam through the fuel. Now on fresh pure gas, using an external tank, it idles rather well, and does rev up without seeming to misfire at all. It just has a bit of hesitation when throttling it up, but does not stall. It may stall when throttling back if it is done quickly. The pressure in the EFI system is running at 38psi. The specifications list that it should be running at 42psi. Could this be an issue? I have not cleaned the injectors other than running seafoam through the fuel, but they are all dropping the pressure equally, about 12-14 psi each on a short burst. SN 0T813499 Thanks for your input!