95 sn fuel pump

[Scottnautique]

My boat will run for several hours with many stops and starts of the engine, when suddenly it won't start again. I've checked spark and I've got it...so I figure it's a fuel problem. On the top of the engine ( PCM pro boss GT-40), there's a shrader valve in the fuel line. While I've never checked the pressue with a gauge, I have pressed on the valve while cranking the engine and get air coming out long before fuel comes. From there it'll occasionally start, but most of the time it doesn't. That's when I pound my head off of things and cry like a child. When I return to the boat the next day I get the same thing...runs great..then nothing.

I've been told the diaphram in the fuel pump may be cracked and I'm getting air on the line as a result. I'm planning on purchasing a new fuel pump but need info, please. Is the fuel pump on this motor easy to find? anything special? Also I've never changed a fuel pump. Will I need to completely drain the tank to change it out?

Thanks for your time.
Scott

[jedgell]

RE: 95 sn fuel pump

I have a similar problem with mine, '95 w/GT-40 also. It always starts great when cold and runs great. After it sits for a while, 10 minutes or so, it's hard to start. Takes a while to start, but when it finally does, it runs perfect. The guys at SkiDim don't know what's up. They thought it might be a vapor lock issue, but I haven't been able to confirm that. I replaced the low pressure fuel pump last year, that didn't do anything. I checked the fuel pressure and it's fine. The high pressure fuel pump is about $360 the last I checked, so you want to be sure that yours is bad before replacing it. Both the low and high pressure pumps are on the port (left) side of the engine, just behind the exhaust manifold. Just follow the fuel line from the filter and you'll see the 2 pumps.

[nch20skier]

RE: 95 sn fuel pump

I just replaced my high pressure fuel pump (96 5.8 GT 40 HO EFI) for $175.00. See attached thread below. You may have a small hole in the hose that is causing the problem......Not sure but it is worth checking out.

http://www.planetnautique.com/index....ic&t=12154

[Scottnautique]

Thanks for the info. I spoke with a mechanic today who works on PCM motors and he suggested that I start with replacing the fuel pump relay ($12). His suggestion is that maybe it's getting hot or I have a corrosion issue on the pins. I'll try anything at this point.

[johnsugar]

Jedgell, I have the same problem. After running all checks it points to the high pressure pump. I found this place to get the pump at a much cheaper price than anywhere else. http://bpi.ebasicpower.com/pc/CARP60...tage%2C+GM+MPI John

[nch20skier]

The picture of the pump does not match what I removed from my 96 GT 40. Is your boat powered by Ford or Chevy?

[M3Fan]

Re: RE: 95 sn fuel pump

I just replaced my high pressure fuel pump (96 5.8 GT 40 HO EFI) for $175.00. See attached thread below. You may have a small hole in the hose that is causing the problem......Not sure but it is worth checking out.

http://www.planetnautique.com/index....ic&t=12154

FYI, the 95 and 96 GT40 motors use different HP fuel pumps. The 95 GT40 did not have the FCC.

[jedgell]

RE: Re: RE: 95 sn fuel pump

I replaced mine a month or so ago and it took care of all the problems, everything runs great now! Got the HP pump at SkiDIM for $320