F225 Fuel Pump?

[Captaintfb]

Hi All -

I'm baffled - twin F225 setup on a 28' Contender. 2007 motors with 250 hours (one week out of warranty!). Cruising along like normal at 3500 rpm and the port motor begins to sound like it's missing and starts losing rpm's. Increasing throttle kept it running, but when I pulled back to idle, it stalled out and would barely restart. Could not put it into gear without the port motor stalling. Limped back home on 1 engine.

Pulled the cowling off and turned the key to on position, and the low pressure fuel feed pump runs continuously. All the fuel filters were crystal clear and clean. Low pressure pump verified to be definitely pumping plenty of fuel. I'm used to the high pressure pump running for the 5 seconds on start up, but not used to ever noticing the low pressure pump run. Hooked up the Yamaha Diagnostic software program, and the high pressure pump passes in the stationary test. The low pressure pump failed because it was on before the test even started. Replaced the low pressure pump with another one from a spare motor and same results. Checked the float and valve in the VST and all appear fine.

Put it all back to together,low pressure feed pump always on, started the motor, and it ran fine for about a minute, then the problem instantly came back. Anyone have any idea what I've got here?

Thanks!

Tom

 

[yamamarinetech40]

Re: F225 Fuel Pump?

Well, if you had called Yamaha customer service, they would have said no problem, we will 'good will' the repairs...they do this on regular basis, very regular, even way longer out of warranty, and they may still. But if it's been screwed with(tool marks, not perfectly factory condition) then the dealer is gonna tell and you'll get the bill before you get your boat. Why didn't you? Anyway, IF the VST is indeed ok and IF the replacement pump is good, then the controller(ECU) is faulty(doubt it) or you have a bad connector/connection giving the pump a ground(how yamaha completes circuits, with ground)....should be very easy to find. Since you are already playing tech, take the ECU off other motor and put on this one...problem stays...it's in the harness. ONE THING....there were some problems with SOME harnesses getting water in them from water pressure senders in 07, you may or not have one(optional). You could pull connection there and shake, see if you get water droplets or any signs of water, also you could check some other connectors. We saw a couple with water traveling quite a ways through wires(under pressure you see).

 

[rodbolt]

Re: F225 Fuel Pump?

what is the fuel rail pressure?
some of the command link equipped engines did have some sensor issues.
07,unless its a commercial motor should still have warrenty.
the low pressure pump on that engine isnt supposed to run at key on engine off and it only runs in spurts bekow 1800 RPM.
all the low pressure pump does is keep the VST full of fuel, from there the high pressure pump keeps it running.
so both pumps can make noise but what is the actual rail pressure?

 

[Captaintfb]

Re: F225 Fuel Pump?

Thank you for your responses. I will check the fuel rail pressure, and try swapping out the ECU on Monday or Tuesday when I get a chance. Will also check with my dealer on warranty status on Monday as well. I'm in a very remote location (out island in the far flung Exuma Island chain in the Bahamas) and my dealer is 70 miles by water away. So - taking a disabled boat that far is a very costly and time consuming venture, and generally not worth the cost if there is any way to fix it on site. Also - it is used commercially (law enforcement) so that generally reduces or negates my warranty anyway.

that the low pressure pump was running with key on engine off was my concern as well. In the old days, it would have just been the relay - now a days, I'm a little out of my league!

 

[rodbolt]

Re: F225 Fuel Pump?

while your checking carefully inspect the back side of the ign coils for signs of overheat/melting.
there were a few cases of ECU failures on the 12v coil primary side that would not only fry the coils but would take out the ECU as well for no apperant reason.
careful swapping parts,dont want two dead engines.
at keyon engine off the pump 12v+ supply is on both pumps,the ground path is controled by the ECU.
same as the ground path for the ign coils primary side.
when running below 1800 RPM the low pressure pump runs about 10 seconds on and 20 seconds off. all is controled by the ECU.
rare as it is you may have an ecu failure.

 

[Captaintfb]

Re: F225 Fuel Pump?

More testing results:

With motor running (poorly) rail fuel pressure read 40PSI on my guage at idle, 38 psi at 2800 rpm.

Tried swapping out ECU, with no change whatsoever in engine running performance or turning off the low pressure pump. Removed and examined all the coils and wiring, and all looked good. Tried swapping out what I believe is the Fuel Pump Isolation and control Box (Small box mounted inside the cowling just under the fuel pump and VST) with no change. Motor is not equippped with a water pressure sender - no water noticed in any of the connections (checked several of them). Reran diagnostics with no luck there. Engine monitor record as follows:

4.Engine Monitor
Engine speed 2871 r/min
Intake pressure 55.99 kPa
Intake pressure 17.01 inHg
Atmospheric pressure 665 hPa
Atmospheric pressure 19.7 inHg
Battery voltage (12-16) 13.7 V
TPS voltage (0.5-4.5) 0.825 V
Throttle valve opening (-1-90) 3.3 deg
Fuel injection duration 1.83 ms
Ignition timing BTDC 20 deg
ISC valve opening 40 %
Engine temperature (below 120) 63.3 ?C
Engine temperature (below 248) 145.7 ?F
Intake temperature (below 70) -28 ?C
Intake temperature (below 158) -18 ?F
Oil pressure (below 842) 593.4 kPa
Oil pressure (below 122) 84.4 psi
Shift position switch ON
Shift cut-off switch OFF

Noticed one new symptom: When I start the port motor, the speedo automatically goes up to around 50 knots. If I start only the starboard engine, speedo works like expected, but then when I add the port motor, or run the port motor on it's own, speedo goes to 45-50 knots. Don't know if that is a related symptom or not.

Tested the harness for shorts to ground and found none except fot the one pin that is supposed to be ground.

Very baffled and pulling out what little hair I have left!


Tom

 

[smartcaddie]

Re: F225 Fuel Pump?

It seems like you have all the diagnostic tools you need to test your engine!!, 2 things.. did you check allready your fuel for water? and try to check for the fuel regulator.. its on top of the VST remember that there is an o-ring from the vst that you need to replace every time you open it.. in this engine i really do belive that both pumps are supposed to run to start the engine and keep it running. was the fuel pressure in your last test 38psi before it died?

 

[rodbolt]

Re: F225 Fuel Pump?

are you rigged with command link guages or the 6y5 digital?
you have a few isues going,
Intake pressure 17.01 inHg
Atmospheric pressure 665 hPa
Atmospheric pressure 19.7 inHg cannot happen, unless your in the midst of a record setting cyclone atmospheric should be in the 29.5 to 31 inch range.
with that throttle opening your intake pressure should be closer to 12"Hg,(note the japs inversed "Hg with PSI).
tricky but trust me.
years ago we measured intake vacum with carburtors, with EFI we measue manifold pressure which is inverse to manifold vacum.
so with the old carb method we would normally see 18-20"HG the same with the intake pressure method we would expect 11-13 PSI.
depending on atmospheric pressure which is usully 29.5,bad weather, to 31.5,good weather.
TPS voltage looks good, with key on engine off it should go from about .72 at idle opening to around 3.0 at a wide open throttle setting.
injection duration is way off for the throttle opening,its trying to run pig rich.
engine temp looks ok.
Intake temperature (below 158) -18 ?F? in the Bahamas?
are ya testing in a walkin freezer?
Ignition timing BTDC 20 deg
ISC valve opening 40 %
at that speed/throttle angle, ign timing should be around 5-7*BTDC and the ISC should be about 70%.
carefully test the ISC using the dynamic test method to see if the RPM and the ISC change. occasionally you will see the ISC stick mechanically and overheat the ecu causing it to fail.
stupid ECU
check to make sure the intake air temp sensor connector is plugged into the sensor at the lower inner port side of the airbox.
if its unplugged a high idle can result along with the -18* reading.
all the sensor can be tested,along with their respective input,output and reference voltages using a multimeter and the sevice manual.
occasionally if the ISC is mecanically stuck open the ECU will keep trying to close it and will read a smaller % than the physical percentage.
trace the gray hose from the ISC to the back side of the coil holder with the flywheel cover removed,unplug it and BEING VERY CAREFUL OF THE MOVING BELTS run the engine using your thumb to throttle the air.
all the air that engine burns at idle is controled by that ISC valve so you can use your thumb as an ISC.
another sign of ISC failure is it gets over about 215*F when running and can cause the ECU to go nuts and even fail.
thats why I said DO NOT start parts swapping or you may have 2 dead 965 dollar ECU's over a 300 dollar part and still have the 300 dollar part bad.
please quit the swapping unless advised.