Fuel problem

I have a 2000 Yamaha V-Max OX66 150 hp motor. It had been sitting for nearly 2 years so the gas in the tank was at least 2 years old but did have Seafoam in the tank. Went to start it a few days ago and it would not fire. Tried putting gas directly into the cylinders and it started but ran only until it burned that fuel. Here is what I have done so far with little no no success.
1) new plugs (early on)
2) Checked for bad fuses, found none
3) Found that the fuel pump was not running when the key was turned on - Took apart the VST, removed the pump and connected the leads to 12 volts. No luck so after reading here i connected oit to 24 Volts and it started to work. It then worked on 12 volts. Reassembled the VST and again no fuel.
4) checked for leaks in the hoses - none foud
5) drained the entire fuel system, tank and put in fresh gas.
6) used carb cleaner in the the throttle bodies and fuel rail - no luck

I can see fuel going into the throtle bodies when trying to start it. I dont have a gauge but there doesn;t seem to be any pressure on the shrader valve. I checked it when turing the engine over. Some gas does come out but it by no means squirts out.
I don't know if this is a fuel pump problem, injector problem, etc. I would appreciate any assistance.

Thanks

Jason

[boats.net]

Sounds like a fuel pump problem, should have 30-35 psi at schrader valve.

I was thinking the same, however, i dont know alot about these motors so I am a bit hesitant to spend $650 if it turns out not to be the pump. With that valve having that pressure, would it feel like i was pressing a valvae stem on a tire as far as the pressure i would feel?

This unit has no carbs. It is fuel injected. Does it even have jets? It has injectors and a fuel rail.

[boats.net]

You need to get a gauge and check fuel pressure thats the only way you will be able able to tell if have enough pressure or if losing pressure.

[jb123]

are the lp pumps filling the vst ?

[bigfish1229]

do you have spark? out of curiosity.

When i used the squeeze bulb and had the hose on top of the VST removed gas did come out of that hose. I had the hose off when i primed the system after draining all the old gas out of it. I never tried blowing against that hose to see if the lp pumps allowed backflow of gas into the filter. The VST did fill with gas as was noted by the pump squirting gas out of the top of it.
There is spark on this unit. I have put gas into both sides of the motor and it will fire and run a short time on that gas.
More than once we depressed the schrader valve and several times a very small amount of gas did come out but never did we appreciate any real pressure behind it.
When the gauge is used do you just have to turn the key on(allowing the pump to run) or do you need to turn the motor over?

Well...as i thought it was the fuel pump. Not knowing all that much, I had to get a pro opinion before spending $650. He thought that it may have been the fuel regulator but that checked out OK. The pump barely pumps. Hopefully when the new one is installed, it will run and there will not be any further problems.

[pancake]

electric fuel pump Voltage?

please post a followup to this. I have a 150hp 2 stroke 2001 hpdi and think my problem is the same. Do you know how much voltage is going into the fuel pump?

[Tucker]

I believe the voltage is variable. The pressure regulator sends a signal to the resistor to reduce voltage to the HP pump to slow it down or increase it with demand.
What I don't understand is why this pump goes bad. It's not unlike the pump on a car. Only the pump on a car has to pump fuel 20' or so to engine. On these motors it has to pump fuel 12" or less to the fuel rails. The pumps on cars last a lot longer.

I should find out early next week. I am not sure why my pump went bad. I suspect it was due to varnish buildup. A thread here said to briedly hook up the pump to 24 volts to break free a stuck pump, which mine was. I did that and it spun free and then ran on 12 volts. What I wonder if by doing that it actually stripped the plastic impeller internally (due to increased power, too much torque). Or by trying to start it several times with a stuck pump caused the damage. A mechanic told be that by just reversing the electrical wires and running the pump in reverse can sometimes free up a stuck pump.
I did connect a meter to the top of the pump and if memory serves the voltage was 13.9 or so. That was when i turned the key on and not trying to turn the motor over.
I wonder if your HPDI (High Pressure Direct Injection)has a much higher fuel pressure than mine. Mine should be around 35 psi.
One thing i tried pancake was taking the hose off of the top of the pump and then run it. The gas that came out was under very low pressure. It didn't squirt. It was only slightly more than a dribble.

[pancake]

electric pump

thanks for the info . i have about six volts going into the pump on my motor with the key on. That seems low . i wonder if the voltage is variable as you mentioned? i beleive that my pump is also frozen though, i'll try to free it up and if that fails ,then will replace the pump. The pumps are outrageously overpriced though.

Yea tell me about it. Im replacing mine. I would try just hooking the wires in reverse and keeping with the 12 volts first, rather than connecting it to 24 volts. That will just spin the pump in reverse and that may be enough to free it up.

[Tucker]

Forgive me if I sound stupid lund but you checked the filter at the bottom of the pump right? Someone said it is a 2 or 3 micron screen and if you had all the varnish you say, it's gotta be clogged. I have the same engine and I just cleaned mine, it had an appreciable amount of crap on it. I thought these HP pumps either worked or they didn't. I didn't know they could trickle. I heard it said here about the 24-volt thing but I don't know if I would reverse the polarity unless someone here has tried it. Still don't understand why the pump would go bad by itself. Compared to a pump on a car it doesn't have a hard job. I believe that pump is about $700. I would wait and let some of the heavy weights chim in. Let's bump this to the top.