150HPDI 2003 Missing at High Rev

"Hello everybody, new to this

"Hello everybody, new to this forum and I would really appreciate if somebody can help, I have twin 150HPDI 2003 counter rotating in my boat, low hours, the starboard motor at times being running OK at, lets say 3500, suddenly goes down to 1800/1900 and kind of misses a little and no matter if I give it gas it stays there, I have to turn it off and on again for it to regain revs and starts to work fine, it can do it several times a day or simply not do it for days at a time, what do you think is the problem? I have changed the fuel filters, the inner filter on the motor and the outer (water separator/filter) one on the boat, there is a little kind of black check valve just before the inner filter on the motor and was changed as well, new spark plugs, premium gas, I have to mention that the port one works perfect same gas and manteinance, any ideas?
Thank you in advance."

did u clean the VST
change HP

did u clean the VST
change HP filter
how are the fuel pumps

"there are a lot of filters on

"there are a lot of filters on hpdis, primary filter on motor,in vst tank on pump, medium pressure filter on top of vst, filters in high pressure pump, filters in the injectors."

"i agree with jit, definately

"i agree with jit, definately change med pressure filter {metal canister on top of vst tank}."

"Wow, I did not know there wer

"Wow, I did not know there were so many filters, I am going to change them and I will post my experience with the new ones, thank you everybody for the fast responses and great help!"

make sure u use the metal clam

make sure u use the metal clamps for the high pressure side filter

"I had a similar problem with

"I had a similar problem with my 04 F150, had the injectors cleaned and it's been fine since, just did oil and fuel filters on it. The dealer didn't even know what I was ordering when I gave them the part number for the VST, and the Med press filters??? But since doing the injectors I've put 20hrs on it with no problems"

"Hello, thank you for the extr

"Hello, thank you for the extra information, I guess I will change all filters and clean injectors, I will not leave anything out of the picture so I do not have to do it twice, thanks again to you all, you has been very helpful!"

"cleaning the injectors on a h

"cleaning the injectors on a hpdi maybe a bit more involved than on a 4 stroker, see how you go."