2001 150 HPDI Problem

[Sparkieboat]

how did the mechanic test the fuel pressure on the fuel rail? I am just curious if he hooked up a computer or some type of manual gauge. Also did he check to make sure the ECU was properly grounding the pump? I would make sure he checked it out good before shucking out big dollars for a new pump. He may have checked these things already, but I would be sure. the pump will not work if the ECU does not "tell" it to.

[gearhead74]

I will call him tomorrow and find out how he tested the pressure and if he ran the codes again. Thanks

[gearhead74]

Okay, I got the boat back today and thought I would go back through the high pressure pump one more time before sending it in for a rebuild. I got a bit more brave and went into the piston and leaf valves at the heart of the pump this time and found that the piston was sticking in the compressed position due to varnish and crud from sitting with old fuel. The two parts that make up the piston and sleeve have a very tight tolerance and can easily get gummed up from sitting. I got the piston and little sleeve all cleaned out and moving smoothly. Long story short, that was the problem and the motor runs great. So when the dealer says they cant repair the pumps and have to send them off for a rebuild I would check that first. Probably saved the guy over $1000
Thanks a lot guys for the all the help. I hope this can save someone some cash in the future.

[Sparkieboat]

that is great. I would still want to check the current fuel pressure on the rail just to make sure the pump is working at full capacity.

[gearhead74]

Do you know where I can get a gauge that will connect to the rail fitting?

[Sparkieboat]

I am not sure that you can. you may have to monitor fuel rail pressure from a computer.

[99yam40]

May need to search back through Rodbolt17's posts to see if he said anything about measuring high pressure on HPDIs.
Maybe by measuring the voltage that the computer looks at would be a way without the computer program.

[boats.net]

There are filters inside high pressure pump but Yamaha does not offer replacement filters for it, if you are only getting 50 psi(VST pressure) then probably needs to sent off and rebuilt. The HPDI engine will run at low speeds without the high pressure pump operating, engine will run on VST pressure.

[99yam40]

boats.net

Is there a way to measure the high pressure rail without the computer?

[gearhead74]

I found a few high pressure digital gauges online but they are very expensive @ about $850 and then you would need some sort of adapter to make the connection to the rail.

[boats.net]

Yamaha doesn't offer any kind of adapters to connect a gauge, not sure where you might find one.

[rumlefish]

You can measure the voltage from the sensor but you would need a jumper harness or back probe with a DVM at the pink and black should see 3 volts which equals about 700 psi i believe or hook up computer and monitor it.You want to make sure you got good pressure or you may cook a piston.

[allancpc]

Okay, I got the boat back today and thought I would go back through the high pressure pump one more time before sending it in for a rebuild. I got a bit more brave and went into the piston and leaf valves at the heart of the pump this time and found that the piston was sticking in the compressed position due to varnish and crud from sitting with old fuel. The two parts that make up the piston and sleeve have a very tight tolerance and can easily get gummed up from sitting. I got the piston and little sleeve all cleaned out and moving smoothly. Long story short, that was the problem and the motor runs great. So when the dealer says they cant repair the pumps and have to send them off for a rebuild I would check that first. Probably saved the guy over $1000
Thanks a lot guys for the all the help. I hope this can save someone some cash in the future.

I have a 2005 Yamaha 200 HPDI with approx 200 hours. Bought the boat and had to put it in storage for family reasons. Pulled it out of storage after 2 years, took it to shop and had mechanics go through the motor. Shop reccomended 100 hour service, drain the fuel, change filters, fluids, etc. I agreed and they serviced the boat.

Boat sat for 6 weeks - I dropped it in the water today and started right up, idled perfect and sounded great. When I went to get on plain the motor reved up and then shut down, reved back up and shut back down. Like a rev limiter. Boat never got on plain, took it back to dock and brought it home.

When I got home I ran the motor at idle and like other times it idled perfect, but when I throttled up, it did the same thing as when it was on the water.

Does this sound like the problem you were having?

Thoughts?

Thank you

[99yam40]

After you read this thread, I would think you would take it back to the shop that did your service and have them check the fuel pressures to see what is going on.