Wrong Prop??

[alldodge]

The pump might provide less pressure as it works and takes some time, or could be a gas vent issue so might be drawing a vacuum, or might be the antisiphon valve causing a restriction and pump has issues after a bit.

Can be many things.

If it was a carb and fuel started getting less it would start to back fire from getting lean. With fuel injection the sensors read there is less fuel so it retards timing to keep from that happening.

I'm just trying to rule things out, and may be going in the wrong order, but just my thoughts

 

[TonyMcbride]

Thanks, Again ! Obviously more complicated than I'm used to! LOL! I'll update on my progress after I change out the Fuel filter..

 

[TonyMcbride]

Ok, that wasn't bad..replaced fuel filter. No water at all in it. Poured contents in my wife's" glass measuring cup, exactly 12 oz..is there a screen somewhere that could be impeding flow?

 

[alldodge]

Was filter full when removed?

There is a screen on the regulator, but if it gets clogged then the pressure gets higher not lower

You could check the antisiphon valve, but they usually don't go bad, and I would check pressure first. If you do want to check it, its a barbed fitting which is screwed into the top of the tank, and the rubber fuel line that goes to the filter is attached to it. There is a spring and ball inside it

 

[TonyMcbride]

Alldodge, I just tried to start the boat after changing the fuel filter. Took me MANY trys before it finally started. Shouldn't the pump run until the filter is filled up again? Every time I turned the key to on, it would pump for 3 seconds but not start. Even if I just switched to "on" and back to off..3 seconds. Seems to me it would run continuously until filter is full again! No?

Anyway, finally started and I took for test ride..3400 @ WOT and seemed rough..not smooth like when I ran this morning and was SWEET running at 4400 rpm!

BTW, did someone say it can go into a limp mode and limit rpm because a sensor thinks the engine doesn't have good oil pressure? Said it is not the oil reading at the console..different one.

 

[TonyMcbride]

PS.. the fuel level in the old filter was about 1 inch from the top when I removed it., and had no water in it..

 

[alldodge]

Shouldn't the pump run until the filter is filled up again?

No, and recon I should have mentioned something about that. The 2-3 second run time is just the ECM checking to see if everything works before you crank. It takes a bit to get the fuel up, and many just keep on/off and push in the shrader valve until fuel shows up before cranking. Sorry should have said something

BTW, did someone say it can go into a limp mode and limit rpm because a sensor thinks the engine doesn't have good oil pressure? Said it is not the oil reading at the console..different one.

If oil pressure goes low enough it will cause the ECM to reduce if not shut the motor down. Are you getting low oil pressure?

PS.. the fuel level in the old filter was about 1 inch from the top when I removed it.

This is a good clue
The filter should have been full of gas, and even had a bit spill out when the filter broke seal with the housing. So either there is a restriction, or you have a weak pump. Need to measure fuel pressure

 

[TonyMcbride]

Thanks, Alldodge! I suppose I should check my fuel pressure next? So, If I understand correctly, the fuel pump can be "somewhat" working? Wouldn't happen to know where it is located, would you? LOL!
Oh yeah..forgot to say guage on console says running about 45-50 psi oil pressure.

 

[alldodge]

Pump is under the port side motor mount

 

[TonyMcbride]

Alldodge, I spent the day trying to hook up the pressure tester for the fuel pump. Nothing but problems..I couldn't find a Schrader Valve so I tried to go straight into back of throttle body with a TBI adapter? Anyway I couldn;t get it to thread in. Good thing I have the tester from Autozone for 3 days! LOL!

 

[TonyMcbride]

Is this the adapter I need?

 

[alldodge]

TBI motors need a fitting so pressure can be measured Merc part number 91-806901 and expensive for what it is