5.7 liter Bayliner Alpha One EFI

[Wheelman81]

Engine bogging and sometimes dies after running over 10 or 15 minutes at 3000 rpm . Engine will run fine all day long at low cruising rpms (under 3000). I have changed water separator and drained and refilled fuel tank and new plugs and wires oil change as well Also replaced flame arrestor. Not sure if this is fuel related or some kind of heat sensor is shutting the boat down due to over heating as i have no working temp gauge. I took to mechanic shop and the guy changed the water pump and after that did not work he was telling me it might be the exhaust manifolds or the thermostat. In my opinion he should have changed the thermostat before or with the water pump if he thought the water pump was the problem. So I read reviews on his shop and realized it was no longer owned by the same guy I had been dealing with for over 10 years so I am gonna have to travel a ways to a new mechanic. Any help would be greatly appreciated.

 

[alldodge]

Need a serial number, but from your other thread with the same issue it does list as a 1997

Not sure if this is fuel related or some kind of heat sensor is shutting the boat down due to over heating as i have no working temp gauge

Being an EFI it should have a 160 degree thermostat. Also don't think you have a heat issue as yet, bickup an IT temp gun, they are about $15 at hardware store (HD, Lowes, online, etc). Measure what the temp is at the thermostat housing.

Go to a Radio Shack or other some electronic parts place and pickup a 12V resistor LED (cost under $1. Then get a paper clip and find the DLC connector near the ECM. Install the paper clip and the LED in the direction shown (note the red or positive in pin F). Turn key ON, then start counting flashes. Normal will be the number 12 (flash, short pause, flash, flash, flash, then longer pause).

The 12 will flash 3 sets then stop. If there are any other codes, then they will also flash in a pattern.


https://forums.iboats.com/forum/eng...y-overheating-and-bogs-down-to-idle-need-help

Something else you can do is get a fuel pressure gauge (auto parts house loaner) the can read 100 psi. Then need a Tee fitting to connect between throttle body and fuel line. The fitting is part number 91-806901

 

[Wheelman81]

Thank You AllDodge I will give those idea's a try. I did not realize a temp gun was so cheap. Also I live in a small town where I should be able to borrow a fuel pressure gauge. I took it out yesterday and took the fuel filler cap off when the problem occurred to check if it was a fuel tank vent problem and it seemed to make it worse. Also what is the correct psi of fuel?If it is not getting the correct psi at the T fitting then do you think I have bad fuel pump or what do you think?

 

[alldodge]

You should have 30 psi with it running. If pressure is low, then could be a restriction to the pump or weak fuel fuel pump or pressure regulator. If you see 30 when idling, leave gauge on and take it for a run to watch

 

[thumpar]

I doubt you are overheating. The alarm uses a separate switch from the gauge so that would go off if overheating. Do you have the VST or cool fuel?

 

[achris]

Engine bogging and sometimes dies after running over 10 or 15 minutes at 3000 rpm . Engine will run fine all day long at low cruising rpms (under 3000). ....

This sounds like restricted fuel flow. May be a clogged tank vent line, allows enough air in at low consumption, but not enough at higher flows.... Loosen the tank filler cap (so air can get in) and take it for a run... It may not be the problem, but it will rule it out... (and it's a 'cost nothing' test)

Chris.........

 

[Wheelman81]

Thank you all for the advice. It will be a few days until I can take it out again and try the things you guys are telling me to do to test things. As for the col fuel system I have no clue if it has VST or cool fuel it is all stock it has been in the family since bought new so basically one owner. i took the fuel filler cap off but just to let it idle a bit should i leave it off while I open it up on the water when the problem is occurring? Thanks again!!

 

[achris]

.... should i leave it off while I open it up on the water when the problem is occurring? Thanks again!!

Yep.