Fuel starvation yamaha f225

[marchmadness]

yesterday I picked up my boat. At the same time,after numerous calls, I got a call back from Yamaha tech support, They are going to send I guess the next level tech to look at my issue.

[oldmako69]

Great. Please post the results.

[marchmadness]

After all this I hope that I can post a RESULT. I haven’t been given a time but hopefully soon

[marchmadness]

Yamaha wants me to put the boat back in the water and have the mechanic download information while the boat is on door load. Today before I was putting the boat in Iran the motor in the bucket and warmed it up and I shut it off. When I restarted the motor the lift pump came on and ran continuous at idle for at least three minutes before shutting off. When the pump was running I could feel the fuel passing through the l relief valve. I emptied the VST but it was full. At idle isn’t the lift pump supposed to still cycle on and off.

[99yam40]

Yamaha wants me to put the boat back in the water and have the mechanic download information while the boat is on door load. Today before I was putting the boat in Iran the motor in the bucket and warmed it up and I shut it off. When I restarted the motor the lift pump came on and ran continuous at idle for at least three minutes before shutting off. When the pump was running I could feel the fuel passing through the l relief valve. I emptied the VST but it was full. At idle isn’t the lift pump supposed to still cycle on and off.

what did you actually mean when you said door load?

I also thought it should cycle, but not sure how long it should run at 1st .
key on to be sure everything is filled up

how did you monitor it running that long?

[marchmadness]

Sorry typo under load, I hooked up my test light to the pump when I restarted the motor and se my phone on timer and it was at least 3 minutes before it shut off

[fairdeal]

never experimented to see what happens with my engine -
but I've always wondered what this statement in the F225 Service Manual means:

[99yam40]

Sorry typo under load, I hooked up my test light to the pump when I restarted the motor and se my phone on timer and it was at least 3 minutes before it shut off

the pump should have power as long as the key is in the on position, the ECU will connect and drop the negative to make it run.
So I hope you hooked it up to see this.

also when you fired it up did it run at a fast idle at 1st?
that could keep the motor running at 1200 and above, keeping the pump running as fairdeal stated

[marchmadness]

the lift pump doesn’t start until the motor starts the high pressure pump comes on at key. So my pump is running continuously over pressurizeding the system. So why

[99yam40]

I would think the lift pump should come on at key on to fill the VST
what RPM does your motor run at when started cold?
how long does it take to drop down to normal idle RPM?

[marchmadness]

At cold I get around 1k rpm and it drops down in a few seconds.

[99yam40]

I though that they would run at a fast idle until they were warmed up,( temp sensor) and then drop down to a normal idle speed

[pstephens46]

Not sure if it matters but I thought these V-6 motors revved up over 2000rpm at start. For a few seconds.

[oldmako69]

I would think the lift pump should come on at key on to fill the VST
what RPM does your motor run at when started cold?
how long does it take to drop down to normal idle RPM?

From what I have seen with my 2005 f225's....

The engines never run at fast idle when started. Winter or summer, they simply idle around 7-800. If they are supposed to achieve a fast idle, they're busted. Or, fast idle is only about 100 rpm higher than normal.

The Lo PSI pump begins its 10-20 operation after the engine has started and is at idle and below 1200.

The lift pump does not run at key on, but the HIGH PSI pump does in order to pressurize the fuel loop. The VST is already full because It does not drain when you shut off the key. The primer bulb is there to fill the VST only when it's necessary. The only time I need to use the bulb to start an engine is when I've been into the fuel system and opened things up, or as is explained in the next paragraph.

One of my motors is behaving just like his. I can leave the boat for 3 weeks, fire it right up without squeezing the bulb and then run all day. Idle, WOT, and anywhere in between. It doesn't matter. But, if I pull over, toss the hook and shut them down for an hour or two, the Stbd motor will start normally but WILL quit about the time I shove the throttles forward to get on plane. It will idle fine, then instantly bog down and die as the throttles are advanced. Then I get to enjoy the soothing sound of that damn warning buzzer.

So, if I think about it, I'll squeeze the bulb before I go. But guess what? Sometimes it will still fail just as described above and I'll have to squeeze a second time. Port motor never does that.

These motors are either great or they're something significantly different than that. Ask about my VST.

motorboating.png

[marchmadness]

So let me go over again what I have found. Oldmako you should check what I have with yours as I stated in post 169. If the lp stays on for 3 minutes at idle then shuts off. Why is the ecu sending this to the pump. So if I'm a guessing man either the pump shuts off as im powering up or the system over pressurizes keep the relief valve open keeping the system running in a loop ..How do I find out why its doing this.