can't get past 2600 rpms

[molokai bro]

2001 shamrock 420 hrs 5.7 pleasurecraft. Checked compress,spark ,dist and changed ecu at manufact suggestion after test indicated all electronic systems ok. Where do i go from here?

[Jango]

Sounds like all there's left to check is Fuel - Fuel Injection, perhaps Fuel pressure?

[molokai bro]

Thanks but presure is almost 15 lbs at the injecter rail. Computer tells us motor using 1gal at 1000, 7gal /hr at 2000, and 15 gal /hr at 2600 rpms plowing trying to get up on plane. Normal to burn 10- 12 gal/hr cruising. I'm stimied so is pleasure craft and mechanic. Any other ideas would be appreciated, Mahalo , Molokai Bro

[longliner45]

dose the engine miss or cut out at higher rpms? sure you have checked your air intakesand cleaned rakoars and or filters for fuel problems,,,,,,,,water,if that dont help I would go back to manufactureand put it on the computer could be a chip or sensor problem

[molokai bro]

Runs without any miss or any indication until it hits 2600 rpm and then it fells like a governor kicks in . put throtel all the way down and no change.Have changed filters both air and fuel. didn't check injectors as computer indicated it was going thru a lot of fuel? What are rakors? Appreciate any other help,

[longliner45]

raykors ..spelling ? are fuel filters that catch water in diesle engines, ,,sorry for not being to much help.

[longliner45]

dont know if you have em but vacuum lines could be collapsing under strain at higher rpms?

[RHough]

Originally Posted by molokai bro

2001 shamrock 420 hrs 5.7 pleasurecraft. Checked compress,spark ,dist and changed ecu at manufact suggestion after test indicated all electronic systems ok. Where do i go from here?

Did it ever get up on plane and run over 2600?

What has changed since then?

Did it slowly get worse or just stop running over 2600 all of a sudden?

[Ari]

Your exhaust system checked ?Do this engine have RPM kill switch ?set properly?

[molokai bro]

Aloha and a big mahala to all how helped. The boat had sat during the heat for 5 months. Water must have gotten past the 2 fuel filters and corrodided the injectors. so bad that first rail injejtors when disconnected individual didn't change idel at all. corrision even under o ring on alum rail. openings on 2 almost closed at opening don't see how it even ran not alone how it ran smooth.Mechanic said that's the last thing they would check. Verifing injector elecricaly then visually a lot quicker and less expensive than changing the ecm as reccommended by Pleasure Craft and the Marine service center. Hope this might help someone else

[bilgeboy]

Glad you found it, sounds very fixable.

I just wanted to add to Longliner's thoughts. He was suggesting you check the Racor's, and if you don't have them, I think you want to install them.

They are water separators with a filter. Dahl is another popular brand, but nowhere near Racor. They'll save you this aggravation in the future.

Good Luck

Mike

[longliner45]

thanks for keeping us up on it, I was curious,thanks

[gonzo]

Pressure should be around 39 pounds at the rail