Use fuel treatment? Read this!
Posted: Wed Jul 05, 2017 1:12 pm
For those who don't know me, I repair boats and equipment for a living. This is also how I came to own my 32 express, but that is a story for another day. I want to share a story with all about a job I worked on last week as it pertains to the recent threads on intermittent poor performance and stalling.
The patient:'01 Cruisers 3750, twin Cat 3126 diesel
Problem: Port engine starts loosing power after running at higher rpm for a few minutes. Happens sooner every time.
Went through and checked all the basics: fuel filters, valves, fittings, accessories. Fires up and runs great. Connected boost gauge and fuel pressure and suction gauge and took her out for a ride. After about 5 minutes at 2400rpm, she started to loose power, and fuel pressure. After a few checks I ruled out a few other potential problems and decided it was a fuel delivery issue for sure. Switched over to stbd tank and all was well. Back to port and problem returns. Now we are narrowed down from the tank up to the selector valve. Traced all fittings and hoses back to the tank, disassembling every connection to check for blockage. Made it all the way to the top of the fuel tank (had to empty and remove a cabinet to access it) before finding the problem.
The problem: Everybody has seen (and broken) the foil seal on the top of a bottle of antifreeze, brake fluid or FUEL TREATMENT. Does everybody remove the seal, or just fold it open and dump the treatment in? I'm guilty too. What I found was one of those foil seals sucked up the pickup tube and stuck in the inlet side of the tank shutoff valve. At idle enough fuel could get past to run good. At load, not so much. Removed seal, problem solved.
Fuel problems can be a pain to solve. A pressure gauge AND a vacuum gauge on your suction line can really narrow down the problem area. Be careful what goes in your tank, too. I spent most of a work day on this job, so you can imagine the expense. It was not the current owners fault as he just purchased the boat and had never added anything to the tanks, but, of coarse, he has to pay for someone else's mistake. Hopefully this will be helpful to others.
The patient:'01 Cruisers 3750, twin Cat 3126 diesel
Problem: Port engine starts loosing power after running at higher rpm for a few minutes. Happens sooner every time.
Went through and checked all the basics: fuel filters, valves, fittings, accessories. Fires up and runs great. Connected boost gauge and fuel pressure and suction gauge and took her out for a ride. After about 5 minutes at 2400rpm, she started to loose power, and fuel pressure. After a few checks I ruled out a few other potential problems and decided it was a fuel delivery issue for sure. Switched over to stbd tank and all was well. Back to port and problem returns. Now we are narrowed down from the tank up to the selector valve. Traced all fittings and hoses back to the tank, disassembling every connection to check for blockage. Made it all the way to the top of the fuel tank (had to empty and remove a cabinet to access it) before finding the problem.
The problem: Everybody has seen (and broken) the foil seal on the top of a bottle of antifreeze, brake fluid or FUEL TREATMENT. Does everybody remove the seal, or just fold it open and dump the treatment in? I'm guilty too. What I found was one of those foil seals sucked up the pickup tube and stuck in the inlet side of the tank shutoff valve. At idle enough fuel could get past to run good. At load, not so much. Removed seal, problem solved.
Fuel problems can be a pain to solve. A pressure gauge AND a vacuum gauge on your suction line can really narrow down the problem area. Be careful what goes in your tank, too. I spent most of a work day on this job, so you can imagine the expense. It was not the current owners fault as he just purchased the boat and had never added anything to the tanks, but, of coarse, he has to pay for someone else's mistake. Hopefully this will be helpful to others.