2001 VX150TRLZ Low Pressure Fuel Pump Issues

[jr75862]

I am having low pressure fuel pumps go bad after just a few trips out. Does anyone know what could be causing this? I have checked fuel lines for blockage and cleaned VST screen.

 

[99yam40]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

Does it have a lean sneeze every once and awhile?

That can pop the diaphragms

 

[jr75862]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

I'm not sure but what could be causing that?

 

[99yam40]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

lean sneeze is from lean fuel/ air ratio, causes fuel burning in the crankcase over-pressuring the pulse to fuel pumps.

You should be able to see and hear the motor cough or sneeze

 

[jr75862]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

Thanks, that make sense now. I have taken the pumps apart and cannot see any visible hole in the diaphram but when I take them off the engine there is fuel that comes out when I loosen the bolts. Is it possible the fuel could be coming from something else?

What could cause a lean mixture with my EFI motor?

 

[jr75862]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

RodBolt, would you have any suggestions? I've told my local Yamaha dealer the symptoms and they didn't seem to know that a lean sneeze would pop the diaphram??

Thank you 99Yam40 for the info, I never realized that could be happening. I'm scared to take it to a shop for the simple fact that it seems alot of them just like to change parts and I'm perfectly capable of doing that.

 

[cousinabe]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

what has your maint history been?

have you:
1) cleaned and TEST your O2 sensor? housing and draw tube.
2) checked that your lp pumps are in spec? I change mine out every three years.
3) VST cleaned and filter changed?
4) fuel pressure regulator screen cleaned?

I would check your low side fuel pressure, between the engine mounted filter and lp pumps.
Check you VST pressure at schrader valve.
You could also have dirty fuel injectors and screens.

A winky blinky and service manual are essential if you want to service that motor correctly.
Provide more info on what has been done to date.

 

[rodbolt]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

my advice?
find a real dealership.
the 3.1L motors have been known to pop diaphrams very quickly with any lean sneeze since about 1990.
thats a very large bore two stroke,a lean sneze is actually an explosion of a lan air/fuel mix in the crankcase.
on a 4 stroke its called a bckfire and flames will shoot out the carb.
on a two stroke this pressure is contained by the reeds and results in blowing diaphrams and occasionally reed valve gaskets.

 

[jr75862]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

I have cleaned the O2 sensor and cleaned the VST and screen.
I am not sure where the fuel pressure regulator screen is at?
I have changed the lp pumps twice since last year because I can't really tell that my motor is having a lean sneeze but it probably is now that I am aware of the symtoms.

I would like to clean the regulator screen before I take it to a dealer but it seems that according to rodbolt that might be my best option at this time.

I don't want to ruin the motor if it isn't already.

Thanks guys.

 

[cousinabe]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

part #13 is the screen.

http://www.boats.net/parts/search/Yamaha/Outboard/2001/VX150TLRZ/FUEL INJECTION PUMP/parts.html

 

[jr75862]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

Thanks cousinabe. The last time out after I cleaned the VST I didn't pop the diaphrams. I still am not getting the RPM's I think I should be getting,around 5000 tops trimmed up. Could plugs cause a lean sneeze? I am planning on replacing plugs next, I think it has been about 2 years since last replacement.

 

[rodbolt]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

plugs arnt going to solve it.
typically if the regulator screen clogs rail pressure spikes and the engine runs rich.
a clogged injector screen can cause a leanout.
did the O2 sensor get tested for voltage output after cleaning and in accordance with about 3 tech bullitens?
disregaurd any flame test.
gotta look up the VX150,I dont think its a 3.1 most likly a 2.6.
but popping diaphrams typically is either a lean sneeze or poor ring seal allowing combustion gas into the crankcase.

 

[jr75862]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

I didn't check the voltage on the O2 sensor. What is the process for cleaning the injector screens?

 

[cousinabe]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

http://www.boatsetup.com/O2sensor.pdf
disregard bench flame test. It's useless.
Make sure you get RAPID volt fluctuation when testing on running motor.

I have removed my fi screens with pliers gently twisting out. Cleaned with carb cleaner. Replaced.

 

[rodbolt]

Re: 2001 VX150TRLZ Low Pressure Fuel Pump Issues

on the ox66 motors the filters can be easily removed from the injector. somewhere recently I posted a mercruiser part number for the screen.
it was used on some of the late 90's to mid 2000 MPI 7.4l mercs and are about 3 dollars each.
i can remember its a 35- part number.