2004 196 Nautique w/ PCM Excalibur

[buddy 2300]

My boat starts fine on the first cold start, then I run it and after I turn it off and it sits for ten minutes or so, it has a hard time starting on the warm start. I have to give it gas to get it to start. It has good power and runs fine once I get it started.

I put a fuel pressure guage on the fuel system and it is losing pressure after I turn it off. It starts at 40+psi and after a few minutes after I turn it off it drops to less than 15psi.

So far, I have replaced the Fluid Temp sensor, Fuel pressure regulator, low and high fuel pump and overhauled the injectors. Fuel filter is clean. It is still losing pressure. I don't smell gas so I am assuming the tubes are not damaged. I may be wrong in this assumption. Any ideas? Is there a check valve anywhere else on this system? How else could I check to see where the fuel system is losing pressure?

Thank You,

Curt

[j2nh]

There may be a check valve on the top of the tank that is stuck open.

I know there used to be.

[buddy 2300]

j2nh,

Well, the boat has been in salt water and we have flushed the engine after every use. The fuel pressure problem has been this way for several months. Now we have a blown (or corroded head gasket). After removing the top end, the cylinders are damaged and the engine has to be replaced. We are going to replace the engine with a closed cooling system and I will follow up if the fuel pressure problem may be related in anyway. Back in several weeks.

Thank you for your reply. We will also look for a valve on top of the gas tank. We have looked there several times and can't see one, but will try to look closer.

Curt

[j2nh]

They used to be part of the elbow coming out of the top of the tank. Looks like a regular elbow except it has a check valve in it.

Sorry to hear about the engine, closed cooling will help if you venture back into salt water.

[buddy 2300]

Following up on our loss of pressure problem. The engine has been replaced with a GM 5.7L Vortec engine and a full (Crusader Closed Cooling System). We have completed the initial break in and it is running great.

However, the fuel pressure problem is still there. We did pull the check valve (anti-siphon) coming from the fuel tank. It is fine, we actually bought a new one and tested both of them and they are both functioning so we kept the old one in. We also had the injectors serviced and they are all good. If anyone has had a similar problem any feedback would be appreciated.

Curt

[JayG80]

Did you replace the short internal fuel hose when you replaced the high pressure fuel pump?

There is a 3/8" diameter x about 3" long fuel line inside of the FCC. This hose hangs the high pressure fuel pump and suspends it from the top of the FCC. The hose may have a crack in it.

I replace that hose about every 3 years and inspect it annually during fuel filter changes.

This may or may not be your problem but the costs for hose and 2 clamps is under $5 and it is good preventative maintenance anyway. Sounds like your boat runs OK once up and going. When that hose starts to crack open then you feel a loss of power as you throttle up to high rpms.

[buddy 2300]

Thank you for the information and your help.

We did test this hose under 60psi+ and it does not leak. We are currently breaking in the new engine and run it at max RPM's for one minute and there is no loss of power. The engine runs good once started. It starts up fine on the first cold start, then the warm starts don't start well because the pressure has dropped in the system. I am now questioning if one of the new replacement parts could be faulty. There is no gas smell either. Curt