| Author |
Message |
    
Robert Lampkin
New member
Username: bdr1wgz
Post Number: 1
Registered: 07-2009
| | Posted on Tuesday, July 28, 2009 - 07:41 pm: | 
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Stumped, problem has persisited for 2 years now. Engines start and run normal. After some time at cruise 3400 RPM's, start losing RPMS, starts surging. Then if I don't throttle back, she chokes all the way to idle. Will run 2600-2700 all day but not full throttle. They are 454 crusader XLI's EFI's new plugs and cap and rotor, all new colling components as well. The engine that this is happening on has 80 hours. Changed the racor filter as well. |
diver dave
Advanced Member
Username: diver_dave
Post Number: 360
Registered: 08-2008
| | Posted on Tuesday, July 28, 2009 - 08:10 pm: |
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I think that engine is getting starved for fuel. Could be an air leak or a partial blockage. If it were my boat, i'd rig a clear vinyl tube to replace a section of fuel hose just before the fuel pump. Run the boat at cruise and check for air bubbles. If no bubbles, then look for a blockage somewhere, 1st stop being the anti-siphon valve. |
Robert Lampkin
New member
Username: bdr1wgz
Post Number: 2
Registered: 07-2009
| | Posted on Tuesday, July 28, 2009 - 08:22 pm: |
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Thanks, I thought it was temperature issue, the shut off sensors. But I believe you are right. I did replace the fuel tank when I replaced the engine. |
Glenn Radler
New member
Username: moonbeam_v
Post Number: 1
Registered: 08-2009
| | Posted on Monday, August 03, 2009 - 08:36 am: |
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Robert,
Please let us know how you solve this problem. I have a pair of 454XL's (carbureted) that do EXACTLY the same thing. The one twist to eliminating bad fuel in one tank, bad pickup in one tank, anti-syphon valve is my fuel selection valves (I can select which of my two tanks each engine draws from). My power loss problem happens regardless of which tank I draw from. |
Robert Lampkin
New member
Username: bdr1wgz
Post Number: 3
Registered: 07-2009
| | Posted on Monday, August 03, 2009 - 09:06 am: |
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Glenn, I suspect the primary fuel filters are restricted. I have the hocky puck type along with the racor water sparators. Also suspect anti siphon valve. Electric fuel pumps have an oil sensor on them that shut them down with loss of oil pressure, could malfuntion. Could be a blockage in the fuel lines. It is definelty a fuel issue, will let you know. I was chasing temperature issues will no change. Robert |
Robert Lampkin
Member
Username: bdr1wgz
Post Number: 4
Registered: 07-2009
| | Posted on Saturday, October 03, 2009 - 03:39 pm: |
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PROBLEM SOLVED!!!!!!!!! replaced the anti siphon valve, the water/fuel separator filter and last but not least the primary fuel filter(looks like large hockey puck. Replaced the micro screens in the primary filter they were clogged. The engine runs great run up and held RPMS like a champ. Robert |
