'97 Sea Ray Sundancer fuel pickup fitting removal

[khe]

'97 240 Sundancer, 5.7 EFI. When the fuel level drops to 7/8- 3/4, the engine runs rough at idle and below 1200 RPM. When accelerating from idle, the engine runs rough and backfires. Once it planes off, it runs fine.

I filled the fuel tank, everything was fine until the fuel level dropped below 7/8 of a tank. My theory is the pickup tube in the tank is damaged. I removed the large clamp nut from the tank fitting but can't see how to remove the fitting from the tank. The fit is very tight and I am nervous about breaking something. It doesn't want to rotate very easily and it doesn't seem to be a push-in type fitting. The tank is a Moeller polyethylene tank.

 

[khe]

I was able to remove the fitting and the pickup tube was fine - there was not any holes in it or other damage.

The problem occurs after the engine is at operating temperature. The last time it did it (Memorial weekend), I filled it up with fuel and the problem did not occur until the fuel level dropped to 7/8 or 3/4. That is what lead me to believe it was a hole in the pickup tube.

I'm now thinking it may be ignition related. I'm going to assemble an LED and a resistor so I can read any trouble codes that may be stored in the system.

There doesn't appear to be a schrader fitting so that the fuel pressure can be checked. Is there anything I may be missing?