Fuel Pressure 95 PCM GT40

[goodewd]

Been having problems starting my 95 Nautique with PCM GT40. I intermittantly try to start and the fuel pump does not prime like usual - the engine usually starts briefly, sputters and stalls. When this happens, I have very little fuel pressure.

I have changed both relays (fuel pump and ECM), but is still happening. Is there anything else I should try to replace such as sensors or other electrical before trying to replace the high pressure fuel pump? I am not sold the fuel pump is broken because 50% of the time when I turn the key, it primes the fuel system and starts fine.

Thanks for any help with this!

[DanielC]

You can download the GT-40 engine service manual from the downloads section of this site. Do that.
I am not sure if your engine uses the FCC like my 1997 GT-40 engine does.
I still think your fuel system still basically operates the same way as mine. There are two fuel pumps, low pressure, and high pressure. The low pressure pump's job is to supply more fuel volume to the high pressure pump than it will ever need. The high pressure pumps job is to supply a fuel pressure higher than the engine requires, and the fuel pressure regulator bleeds excessive pressure back in to the FCC, maintaining the fuel pressure.

I have seen cases where the low pressure pump loses it's prime, and will not pump fuel, and then it gets primed again, and works fine. Check to make sure you have adequate fuel flow from the low pressure pump. Check when the engine is malfunctioning. You should get around a quart of fuel every 15 seconds.
Also check your fuel pressure, at the fuel rail.

http://www.planetnautique.com/vb3/sh...=Fuel+Pressure