F250XCA dies under load

[99yam40]

Question. does the lift pump also use fuel running thru it to cool and lube the motor/pump?

[ntxwatercraft]

I ordered the LP pump. I will report back after installation. Keeping fingers crossed that this will finally be the answer! I really appreciate everyone’s help.

[ntxwatercraft]

Ok. Before I installed the pump, I double checked the circuit for shorts. I unplugged the LP pump and replaced the #4 fuse. Then I ran the motor for 30 seconds. The fuse did not blow, leading me to believe that there was no additional short. I replaced the LP pump and set out for a test drive. The new pump did not blow the fuse. However, the engine died like it usually does under load between 3000-4000 rpm. I checked the bulb and it was full and hard. It now occurred to me that this may be an electrical issue.

i returned to the slip and began checking my electrical system. Here’s the funny part. I found that the negative cables on the starting battery were corroded and a little loose. I disconnected the battery and sanded all connections and reinstalled.

I then went on a very successful test drive, making half a dozen passes by the marina at varying rpms. No stall! I assume there was a poor connection and the engine couldn’t draw the required volts/amps.

I will take the boat out again on Wednesday. Hopefully, this will be another successful test drive.

Thanks again for your help!

CN

[ntxwatercraft]

Another successful day. Pulled the kids on the tube all day with no stall.. I can’t believe the primary problem was a loose battery connection.

The boat runs great now.

[ntxwatercraft]

After replacing all the filters, separators, injectors, and a fuel pump, it appears the problem was a loose connection on the starting battery. I had no idea that the electrical system could behave like this. I wasted countless hours working on this engine. CHECK YOUR CONNECTIONS!!

[DennisG01]

Glad you got it sorted out, though! Seems like you actually had two issues - poor fuel quality and then the electrical connection... when there's more than one culprit it makes diagnosing even MORE fun, right?