Boat Starting Help

[plav77]

Hi Gang,
I have a 2002 Supra and when I try to start the boat I need to keep the engine turning over for around 30 seconds before it will stay running.
Once it's running it runs great but it's just when I start it. If I turn the boat off after it's been running it usually does the same thing just not as long as the first time.
Anyone have any thought on what I can try?
Thanks. Paul

[CJD]

Is the '02 a carb or fuel injected? It sounds like it's taking some time for the fuel to get to the engine...so a weak mechanical pump if it's a carb...or a bad electric fuel pump that is releasing rail pressuree if it's fuel injected.

[plav77]

Thanks CJD, it's fuel injected

[chris young]

Sounds like a bad check valve to me. I don't know your motor at all, but a lot of fuel injected motors have a schrader valve (just like the one on a tire) on the fuel rail. If it does you can take a standard tire pressure gauge and read your fuel rail pressure. If it starts dropping as soon as you turn the key off your check valve is not working. I don't have much experience working on fuel injection systems, but to the best of my knowledge, most systems have the check valve in the pump and a fuel pressure regulator that dumps the unused fuel back into the tank. Based on your symptoms I'd say the check valve is stuck. If you find the fuel pressure is indeed dropping after you shut down, you could install a new check valve in the fuel line if you don't want to go through the hassle of replacing the pump.

Another thing you can do to see if it's a fuel pressure problem is to turn the key all the way on, but don't start the boat for 5 to 10 seconds. If it starts right up when you go to start, it's for sure a fuel pressure issue.

Good luck, keep us posted

[plav77]

I found the gas pressure valve but my standard tire pressure gauge was too small for it, will look for a bigger one.
Here is a video of my starting issue -
https://www.youtube.com/watch?v=E2jQPsGELvs&feature=em-upload_owner

[plav77]

So I took the boat out yesterday, tank was at half to filled it up wit the best gas and put some fuel treatment in it.
Still had the starting issue but also my boat was dying on idle often. Also when I let off the gas quickly to stop the boat it would die.
At one point it wouldn't allow me to give it gas without dying, I floored it and finally caught.
I'm going to try and replace the Gas Filter\ Water Separator and see if that helps.

[CJD]

Could be a leaking injector is flooding the motor and killing a cylinder until it clears out the extra fuel. A leaking injector is also indicated by dropping fuel pressure immediately after shutdown.

So, bad fuel pump check valve or leaking injector are most likely. A third possiblity is that the fuel pump so just weak, and not getting the full pressure to the rail. If the fuel pressure drops in the system with the engine still hot, the low pressure can cause vapor lock, which also causes hard starting, rough running and bad idle until the injectors clear the vapor bubble out of the rail.

So...rail pressure check is your first step. Give us an idea of the running pressure, which should be steady with the engine idling. And then time how long it holds pressure after shutdown.

[CornRickey]

I pulled my floor this week and found my check valve corroded. Wiggling it with the hose on it snapped on half with little to no force.

[plav77]

17049
I talked to Indmar and Supra and the check valve is part of the bottom of the gas tank.
When checking on part costs with skidim they said usually people can clean the check valve with some carb cleaner but they don't sell the part.
Also the boat has 2 pumps on it a Low and High Pressure Pump.
I'm going to try and find a pressure gauge that will fit on the gas line as my tire one is too small.
How will I know what pump is failing if the pressure is an issue?

[plav77]

Here is the what the pressure does when I turn the key.
Jumps up to 30PSI then quickly drops down.
From what I've been told if the PSI drops down quickly it's likely the pump, if it was a leaky injector the PSI would drop slowly.
Thoughts? Do I need to start it and see what happens to the PSI when it's running?

https://www.youtube.com/watch?v=SHJMRBkthl8

[plav77]

So this is where on my fuel tank I'm told the check valve is.
I'm not sure what one the fuel feed line is but I'm guessing it's the dirty one!
I can't get the hose off as the clamp is twisted, I'm tried twisting it by hand and doesn't work.
Also I tried using a wrench to get it off but it wont turn and with it being attached to plastic I'm worried about breaking it.
I'd be interested to know if people think it's this check valve or the actual pump that is the issue, from what I've been told the pump also has a check valve?
17053

[CornRickey]

Just cut the clamp and replace. Pull each hose to see which one goes to the fuel pump. The fitting coming off of the fuel pickup line elbow is the check valve. It is barbed to receive the fuel hose. Google search for a image of it.