2018 DF90 starting issues

[doubledeed]

I recently have had some fuel issues and wondering if I need to replace the VST tank. Over the summer a friend used the boat and didn't check the separator and sure enough water went thru the separator and into the VST. What is odd is that the engine ran fine for him but when I tried to start it a couple of weeks later it wouldn't start. I checked the VST and sure enough there was water in the bottom and the fuel pump had quit. So, of course this is not covered by the warranty so I pulled the injectors, plugs and the VST the next day. I replaced the fuel pump, checked the injectors and changed the plugs and it started right up.

After the initial start up I ran the boat in idle for about 30 minutes to make sure that there was no more water in the system. The engine did idle a little rough but got better as time went proceeded. Yesterday I got stuck.... My wife and I ran the boat to a friends house about 15 minutes away and then stayed for about 30 minutes. The engine wouldnt start when we tried to leave. Damn! Had to get a tow back and of course it started right before we got back to the dock.

So now I ask the forum- what do I need to replace? I tested the injectors and they seem fine, the plugs were also replaced. In the VST I only replaced the fuel pump and not the float, fuel pressure regulator etc. The repair shop wants $1000 to replace the VST since its not under warrenty due to fuel issues. I can replace the VST for around $500 but want to make sure this is the issue first. Please chime in and let me know your thoughts as I need to get this up and running and keep the admiral somewhat placated with a running boat....

thanks
Dave

[Hoosmatroos]

Hi welcome. Check the VST for internal corrosion. If ok the perhaps you should replace the small filter on the bottom.This is a cheap solution if it's blocked.

[doubledeed]

Thanks Martin!
When I changed the fuel pump out there was no corrosion and also inspected the filter. It appeared very clean. I just dont know what would cause it to not start the other evening. Also, on the 2018 90A models its a pain to service the VST so when I do this again then I would like to make sure it's correct.

thanks again-
Dave

[jHydroman]

You didn't mention weather you drained the fuel tank and eliminated the source of the water.

Just sounds like you failed.to get all of the water out of the system.

Jim

[doubledeed]

Sorry, I forgot to mention that. I did drain everything. tilted the boat all the way up on the trailer and then sucked out the fuel. replaced the separator and drained every line to the engine. I will go check the separator again now though just to make sure.

[Murray]

Have you tried Seafoam or a similar productt?

[jHydroman]

Some of the contaminated fuel may have made its way to the low pressure and high pressure fuel filters, might want to change them.

Jim

[doubledeed]

No water in the separator. Not sure what to do next...

Thanks
Dave Dunba

[Solarman]

Think I'd connect a tube to the injector rail, run the tube into a glass jar, add seafoam to tank, goodly concentration, then turn key on (may take a couple times, waiting between each cycle - so pump isn't running continuously for too long) and flush a quart of good/new fuel with the seafoam in the tank through entire system. Then inspect fuel in jar for water/ other contaminates.

Good luck.

[doubledeed]

So connect a tube from the discharge of the pump into a glass jar? If I connect to the rail it will just go to the injectors right? So just pump a lot of 75/25 fuel to seafoam thru the lift pump, VST and then out of the system correct? Have you ever heard of the fuel pressure regulator going bad?

thanks so much Solarman!
Dave

[redlowrey]

I recently have had some fuel issues and wondering if I need to replace the VST tank. Over the summer a friend used the boat and didn't check the separator and sure enough water went thru the separator and into the VST. What is odd is that the engine ran fine for him but when I tried to start it a couple of weeks later it wouldn't start. I checked the VST and sure enough there was water in the bottom and the fuel pump had quit. So, of course this is not covered by the warranty so I pulled the injectors, plugs and the VST the next day. I replaced the fuel pump, checked the injectors and changed the plugs and it started right up.

After the initial start up I ran the boat in idle for about 30 minutes to make sure that there was no more water in the system. The engine did idle a little rough but got better as time went proceeded. Yesterday I got stuck.... My wife and I ran the boat to a friends house about 15 minutes away and then stayed for about 30 minutes. The engine wouldnt start when we tried to leave. Damn! Had to get a tow back and of course it started right before we got back to the dock.

So now I ask the forum- what do I need to replace? I tested the injectors and they seem fine, the plugs were also replaced. In the VST I only replaced the fuel pump and not the float, fuel pressure regulator etc. The repair shop wants $1000 to replace the VST since its not under warrenty due to fuel issues. I can replace the VST for around $500 but want to make sure this is the issue first. Please chime in and let me know your thoughts as I need to get this up and running and keep the admiral somewhat placated with a running boat....

thanks
Dave

'''''''''''Something does not sound right here, you should have said in your first post how much water you removed from the fuel system especially the vst. What made you change the fuel pump, you done a voltage drop test on the pos and neg wires at the pump and was ok, or you didn't hear the pump run when you turned the key on, or you thought you would start at the pump and change it.
When you changed the plugs did you see water on the porcelain tips, it is a new engine so I would not imagine there would be any corrosion anywhere. For the engine not to start from a water problem would be easy to test, just remove the hose from the high pressure filter fit some hose to the filter and pump some fuel into a clear jar, if there is any water in it you will see it straight away.
Don't replace anything else to you reply back with the reason for changing the pump and how much water you removed from the system.