2006 Yamaha F150 Fuel PSI

[will941s]

Hello All, working on a 2006 Yamaha F150 4-Stroke and need help with some info. Motor was bogging down, hard to start and would cut off with anything above idle. I took a fuel pressure reading at the low pressure pumps, theyre at 13 PSI even. Took a pressure reading at the rail and the needle (vibrated) between 30-42 PSI. I took the system apart and cleaned the VST, all VST parts (Very dirty), changed ALL filters, Cleaned the Injectors (Clogged), cleaned the rail, and put it all back together. Hooked it to a remote tank with fresh brand new gas (have to drain the tank), and started the motor. Started like a champ, idles good with a little hesitation. Idle Air control valve is getting hot within like a minute so I have to replace it. Otherwise heres what I have. Fuel pressure is holding now at about 34 PSI, when you hit the gas it shoots up to about 42 PSI. Let off the gas suddenly and it drops to about 31 PSI. Everytime it changes it levels right back at 34 PSI. When it jumps to 42 it seems like it floods, and when it drops it "pops" or leans. Besides the obvious Idle Control Valve issue.....am I safe to assume the Fuel Pressure Regulator has hit the end of its life? Thanks for any info!

 

[will941s]

Re: 2006 Yamaha F150 Fuel PSI

Hello all, I think I have resolved the issue. Motor would hold a very rough idle, no power through the range and had a slight "popping noise". My fuel pressure would jump to about 40, and drop to about 30 when I hit the gas and let off. When it did stabalize it was juming all around. I changed the idle control motor "which was burning up".....after that no real change, just held idle better and no surging. I cleaned the VST, and the screen inside the VST on the high pressure pump. I took the High pressure pump out and verified it was putting out good pressure by sitting it in gas, attatching a hose to the top with a fuel pressure gauge and putting 12V to it. I changed all the filters and the plugs. I took the injectors off the rail and cleaned them....I know the best thing to do it have them sent off but heres what I did. I took the filters out, and removed the O-rings. Put a hose over the inlet with some creative fitting so I could appy about 80 PSI air and carb cleaner at the same time. I rigged a wire set up with a button to the terminals. I let them soak in cleaner for about a hour and while they were in the cleaner (terminals NOT submerged) hit the button about 50 times to open and close them in the solution. Then took them out and applied my air and cleaner mixture while opening and closing the injectors. As they opened and closed the stream got nice and full. One actually "popped" then sprayed. I flipped them over and sprayed cleaner backward while holding them open, then repeated the process with the hose at the top. Put it all back together and connected the fuel hose to a remote tank with FRESH gas and started the motor. BAM!!!!! Like a new motor. No popping, no missing, revs like a champ. I put about a hour run time in a tank so far and so far great results. FP is holding with very little variation through the ranges and no needle jumping. Next step is.....draining 30 gallons of gas out the tank, re filling it and taking it for a sea trail. I will post results then.

 

[will941s]

Re: 2006 Yamaha F150 Fuel PSI

Got my top speed back, low idle back and runs like a champ!

 

[cousinabe]

Re: 2006 Yamaha F150 Fuel PSI

Great post! Good job.

 

[BaileysBoat]

Re: 2006 Yamaha F150 Fuel PSI

Interesting post, but your fuel pressure readings at idle sound low.
You need 37.7 psi at idle, and 45 psi within the first 3 seconds key on engine off.

When you pull the regulator vacuum hose at idle the pressure should rise.

 

[schematic]

Re: 2006 Yamaha F150 Fuel PSI

your problems will return......failing fuel pump will **** up your injectors AGAIN!