Fluctuating fuel pressure

[seano700]

I have a basic Powder Lites Sage 2 turbo Nytro. Last couple rides I noticed sometimes my fuel pressure is fluctuating about 5psi at idle. Most of the time the needle is pretty solid at 43-45psi, every now and then it starts to fluctuate about by 5 psi. I noticed this my first ride after the really cold weather (sled was stored outside) I put in some isopropyl and no change. Any suggestions?? Thanks in advance.

 

[Lococoin]

where do you have the vacuum line hooked up? vacuum or boost only side?

 

[Hrt Offroad]

My sled was doing the same, but I did the latest PL tweak; welded a bung onto the charge tube and put boost only to the fuel pressure regulator...along with the latest RB3 map. Now it works flawless

 

[seano700]

Thanks!

Thanks for the reply guy's!!! Currently the fuel pressure reg, map sensor, BOV, and boost guage all sense from the same location (downstream of the throttle bodies) I just got the 4th generation upgrades as well, I will try plumb the fuel pressure reg into the new line that feeds the map sensor. I only noticed this after I installed a fuel pressure guage up on the handle bars for some other troubleshooting.

Any special spot on the charge tube to locate the new bung??

Sean

 

[Hrt Offroad]

Thanks for the reply guy's!!! Currently the fuel pressure reg, map sensor, BOV, and boost guage all sense from the same location (downstream of the throttle bodies) I just got the 4th generation upgrades as well, I will try plumb the fuel pressure reg into the new line that feeds the map sensor. I only noticed this after I installed a fuel pressure guage up on the handle bars for some other troubleshooting.

Any special spot on the charge tube to locate the new bung??

Sean

I put mine on the backside of the short horizontal section below the headlight, and then used a 90 deg 1/8" npt fitting with a barb on the other end. The its only a short run (6-8") of vacuum line to go up to the fuel pressure regulator. I'll see if I can get a pic tonight.

 

[seano700]

Just got off the phone with Darren. I thought the new bung in the charge tube was for both the map sensor and fuel pressure reg. If I understand him correct only the fuel pressure reg is to be fed from the charge tube. The fitting he mailed me was a barbed aluminum nipple with male NPT connection. Did you buy a 90 deg fitting with female thread, weld it in, then screw in the supplied connector??? Any help is appreciated Sean

 

[Hrt Offroad]

Just got off the phone with Darren. I thought the new bung in the charge tube was for both the map sensor and fuel pressure reg. If I understand him correct only the fuel pressure reg is to be fed from the charge tube. The fitting he mailed me was a barbed aluminum nipple with male NPT connection. Did you buy a 90 deg fitting with female thread, weld it in, then screw in the supplied connector??? Any help is appreciated Sean

I made a weld bung out of 3/4" solid aluminum round stock (1/2" long) drilled it out and tapped it with a 1/8" NPT tap... then TIG welded it centered on the hole I drilled in the charge tube. It gave me more meat to thread the 90 deg fitting into. It may be overkill, but I'm an overkill kind of guy I'll see what I can do as far as pics go...

I just took the sled for a test run after doing the mod..."0" lag, awesome throttle response and no fuel pressure fluctuation!!!!!!!!!!!!!!!!!!!!!!!!

 

[08nytromtxa]

any pictures?? would like to see how this works

 

[seano700]

Update

Thansk fellas, I just did finished the 4th generation updates. Fuel pressure is much more consistant now. I havent tried it on the snow yet but I see the AFR is 13-13.4 at idle used to be 12.2-12.6 will this hurt anything??