Help, 2000 AN Fuel Pressure Issues

[gmdattilo]

We purchased a 2000 Air Nautique 2 weeks ago. It ran great on the test drive. We took it out last Sunday and everything was fine for the first hour but on the way back to the ramp it died and would not restart. The engine is a TBI Chevy 305. When it would not restart I took the flame arrestor off to see if fuel was spraying from the injectors while I was cranking, no fuel was spraying. I don't recall if I heard the fuel pumps running. After we got it back into storage I did hear one or both of the fuel pumps running when I cycled the ignition.

I measured the fuel pressure at the Schrader valve on the FCC with the fuel pump relay jumped out (pumps have power when ever the ignition is on). I only saw about 10psi fuel pressure. I found a PCM quick reference on the web that says TBI fuel pressure should be about 30psi. My question: Is the Schrader valve on the FCC the proper place to check the fuel pressure? There are several posts I have found that reference a link to an article on fuel pressure at the old site but the links are broken.

[teamseal]

Yes the FCC shrader valve is the correct location for fuel presure check.
I would be willing to bet that if you took apart the FCC canister you would find very little fuel in the canister.
That being said their may be a restriction in the feed line at the tank or somewhere to the low presure pump or the low pump has failed.
If canister is full of fuel then look for dislodged power or ground wire at the high presure pump or pump failure.
Let is know what you find.

[mhaaland]

i your fuel pump is bad i might have the one you need. It's brand new & i'd give you a great price on it!

[gmdattilo]

They run better with fuel in the tank....

Thanks for your quick responses!

I am ashamed to admit this but the gas tank was empty. The gauge and or sender must be screwed up because the gauge is showing completely full. I started to do a volume test on the low pressure pump and got no fuel at all. I had "topped off" the tank before we took the boat out last weekend to make sure the fuel gauge was working but I guess I was filling too fast cause the gas pump cut off right away. It only took about a half gallon so I assumed the tank was full. Once I dumped a few gallons of fresh gas in the tank and ran the pumps for a few seconds I had a solid 30 pounds of fuel pressure. I also got about 24 oz in 10 seconds doing the flow test on the low pressure pump. It was pouring down rain all day today so I didn't put it in the lake but I'm pretty confident that the problem is solved.

I did install a permanent fuel pressure gauge while all this was going on. There is an 1/8" NPT threaded port on the front of my FCC right next to the low pressure inlet fitting. It is ported to the Schrader valve and the outlet to the throttle body. I had a nice stainless rear port gauge that went on there perfectly.

Can anyone offer any advice on troubleshooting the fuel gauge issue?

[teamseal]

Funny stuff!!!

Simple check on the gauge is to unhook and short out the sending unit wire to ground at the tank and see if the gauge moves, and or how it moves If not then more than likely the gauge has failed, if it does move then more than likely the sending unit has failed.

[mhaaland]

Good news! Better than a bad fuel pump or something!