2000 Ski Nautique (GT40) Fuel Pump Issue

I fear it might be impossible to tell. Since the boat is new to me I'm leaning towards doing some preventative maintenance and installing new:

low-pressure fuel pump
FCC fuel filter
fuel pump relay
Internal hose for the high-pressure fuel pump

Would anything else be prudent such as new breaker switches? Here's the current cart at planet nautique (not sure why the hose has no price but I plan to call them tomorrow before ordering):

David,
Before you become a "parts thrower" randomly replacing parts, why not take a look at the poor mans GT40 diagnosis thread? It's one of the many threads with links in the FAQ thread in the maintenance section.

Thanks Pete and Hansel. I'm a little lazy on the diagnostic side, haha. We have a 1 year old daughter which unfortunately doesn't leave me too much time to mess around with the boat. It seems faster to replace parts than do proper diagnostics. In my defense, I also want to get back on the water as fast as possible before winter comes regardless of the cost. :-)

However, I do know for a fact that the fuel system is the problem; I also checked the emergency kill switch to make sure it wasn't causing the problem. The boat never stopped cranking or sparking, but the fuel pressure in the FCC was a nice round 0 psi and neither of the pumps appeared to be working (no sound or vibration). Now that the boat is running again, I do plan to check the pressure at the Schrader valve to determine if the HPFP or fuel hose needs to be replaced.

Based on what I've read (now including the poor man's diagnosis thread) I do believe I am most likely dealing with a partial failure of the LPFP which may be causing a breaker trip. My main concern is to replace the LPFP before I get stranded again, but while I'm at it I will go ahead and replace the FCC filter (I don't know when (or if) it was last replaced). Also, the relay is cheap and takes almost no-time so I just throw it in and it will give me piece of mind that I didn't miss anything.

I will also check the HPFP fuel hose while I'm replacing the filter just to be sure and replace it if I deem it necessary. The inline fuel filter also looks cheap and maybe worth replacing just because. I will check to see if my boat has one first though. :-)

Hansel,

Where is the inline filter located? I haven't yet found any documentation on it. Thanks!

Hi Dave,

I don't know about 2000 model years, but '97s did not come with an inline fuel filter as I describe AFAIK. There is obviously one farther back near the tank like Brian says, but I wasn't going to mess with that, and in any case the idea came from the folks at White Lake who said they were getting numerous calls like mine on boats of my vintage and that they thought this would help. Not sure if it does, but the filter is cheap and cannot hurt (I assume). According to them filters like these were added by the factory maybe beginning in the mid-2000s? (anyone know) so I just bought one, cut the hose a ways back from the LPFP and inserted it. It could be if you go looking for one you may never find one, maybe someone with a 2000 model year can help us out here? But you are right that all of the items you are talking about are cheap. I remember that I spent about as much on the one-day shipping than I did on the parts themselves!

The nice thing about a LPFP failure is that it is easy to spot, since the pump makes a fair amount of noise/vibration (e.g. you can hear it prime when the key goes to "On"). I have two now, and after replacing the relays, etc. I know that both work. But having a backup never hurts.

I am no expert, but I think you are fine. My guess is that if the LPFP gives out the HPFP sucks it dry pretty quickly and then the engine starves for fuel. Every time my LPFP failed it took a few primes to pull from the tank before the pump would eject anything (probably not great for the pump, in retrospect...).

Also, this is my 10 year anniversary post :)

J

Dave the system should hold the pressure with only a 3 psi fall over 3 minutes. If not you may have either a faulty regulator or leaking injector.

lewy2001 wrote: Dave the system should hold the pressure with only a 3 psi fall over 3 minutes. If not you may have either a faulty regulator or leaking injector.

Sorry to revive an old thread. I just have a question about the fuel pressure hold test you mention Lewy.

If I run the boat at idle in the driveway it’s right around 32 psi. If I shut the engine down and let it sit it definitely holds pressure for three minutes. At three minutes it may be dropped to 31.

However, if I key cycle the pumps (engine off) to pump the pressure up to about 37 (max I get), and then do a three minute test, It drops about 4 to 5 psi. So it seems that it doesn’t pass the test at the higher pressure but does pass the test at the lower pressure. Is that bad?

Leaking somewhere, could also be the pressure regulator leaking.

A curious person might wonder what the problem is that you're trying to troubleshoot