1997 240 Sundancer fuel pickup

[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 rotted. 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. Has anyone removed the fitting? If so, how did you remove it from the 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?

 

[KHE]

The problem was a bad distributor cap & rotor. The spring loaded contact that contacts the rotor was gone and it was really burned. I'm surprised the boat ran as well as it did with the problem. A new Quicksilver cap and rotor and the problem was gone.

 

[Espos4]

Thanks for the update.