2005 DF140 bogging down and sputtering

[Mikey_Fin]

Hey all -

Have been browsing this forum for a while on different topics.

I have a 2005 df140 that I am troubleshooting. The motor is rigged on a classic mako. Recently had a fuel tank issue, started smelling fuel, water in fuel and in the racor. Replaced the fuel tank with a brand new tank. I had a 100 hr service done by suzuki tech. Replaced the racor filter. Motor ran fine but now does not... Bogging down.... If I gradually increase rpm, she will maintain, but not achieve full throttle. I have since again replaced the low pressure fuel filter, drained the VST, replaced the MAP sensor, cleaned the IAC. I determined the problem was within the motor by switching to an external tank. I put additives (seafoam and heet) in the external tank and ran the 6 gallons through the motor.

Any ideas what to do next?

Help is much appreciated..

All the best,

Mike

[Zuki175]

I would inspect the high pressure fuel pump inside the VST. On a recent service, I drained the VST and it was 3/4 full of water from bad fuel. Replaced the HP fuel pump and it fixed the problem. Just a thought....

[Harper]

Before replacimg the high pressure pump, I'd first try replacing the filter on the intake of the high pressure fuel pump. Just a very small screen type filter. Slightly over $7.

Then, if the problem persists, do a fuel pressure check before throwing expensive parts at it.

[Mikey_Fin]

Appreciate the very quick response! So the consensus is to pull the VST to get to the high pressure fuel pump? I was hoping to avoid taking off the manifold. Again appreciate the response.

[Seaduck]

on my 2007 df115 you can take the vst out without removing the manifold. First time i took my vst out i removed the manifold. then after seeing a gentlemen on here do it without removing the manifold i tried it. You have to remove the high pressure filter first and then get to the 3 bolts for the vst. you need some standard wrenches as well as a box end 10mm. it is a tight spot but is possible. a lot easier than taking the manifold off. good luck

[Mikey_Fin]

Wanted to provide an update. I removed the VST. I replaced all filters: high speed, low speed, cleaned out VST also replaced the small filter inside the VST. Replaced fuel regulator as well. Boat still will not come up to speed. It runs, but will not rev up. What's next?

[artdf175]

have you checked the tank air venting?

[wibbleman]

Any update on a solution to you problem Mikey_Fin? Had a similar problem at the end of last season and decided to check entire fuel system from tank to the engine over the winter. Found some bad seals, fuel lines and replaced the racor. Also ran a complete flush on the cooling system and have really good flow and telltale....replaced thermostat too. Hoping for a positive result today on startup but still have the same problem of sputtering when give it throttle and no umph. Really think it;s the HP fuel pump and going run electrical test tonight. Was interested in the comment above about tank air venting? Are you speaking of the fuel tank? Don't want to leave anything out ...thanks

UPDATE:
Turned out to be the HP fuel pump bushing. It was torn and the material had degraded to an extent it basically fell apart when I took out the pump. Cleaned everything else in the VST up while I had it open. Hope this helps someone.

[Mikey_Fin]

Wanted to share. Issue was dirty injectors and vst. Cleaned both.

[Dblex418]

Wanted to share. Issue was dirty injectors and vst. Cleaned both.

did you send the injectors off or did you clean them yourself?