225 vmax hpdi cutting out

[gamb201]

I have a 2005 Yamaha 225 VMAX HPDI that has a problem cutting out upon acceleration. It will not get on plane most of the time. I've had it tested by two reputable dealers/mechanics and it is not throwing up any codes on the computer. However, they can't seem to pinpoint the problem, only that their is inconsistent fuel pressure (test run on the water). I have new filters, sparkplugs, fuel pump, shift switch, and have always run ring free with the gas. Does anyone have any idea what might be happening?

 

[cousinabe]

Re: 225 vmax hpdi cutting out

fuel pressure will not throw any codes.
has the vst filter been replaced? pressure regulator cleaned?

what fuel pressure tests did they do? low pressure, vst pressure?

 

[gamb201]

Re: 225 vmax hpdi cutting out

I'll find out more details about the fuel tests tomorrow during business hours tomorrow. Thanks.

 

[rodbolt]

Re: 225 vmax hpdi cutting out

the VMAX 225 HPDI for 2005 is a 3.3L means no O2 sensor and it WILL throw a code for low fuel rail pressure on the high pressure rail.
this can be monitored with a DVM,the diagnostic test lamp or the laptop.
rail pressure is typically 1100 PSI on the high pressure and 50 PSI on the medium pressure and 6 PSI on the low pressure.
medium and low pressure rails are NOT monitored by the ECU.
however low pressure on the lift pumps can lead to low VST tank level that will lead to low medium pressure which can lead to low pressure on the high pressure rail.
code 25 is low high pressure rail indicate but it will only show the code when its active.
do these reputable techs have a minimum of fuel and electrical certifications from yamaha on the wall ?

 

[fisher77]

Re: 225 vmax hpdi cutting out

hey,
did you ever find out what the problem was with your vmax? i have a 2005 vmax hpdi 250 that cuts out around 4k while accelerating. but when the boat gets up on plane it has no more issues.