Returning Fuel system Question on Nytro

[seano700]

I recently installed a bung into the fuel injection rail on my Nytro in effort to make it a returning system like the apex. I took the sled out today and now my rising rate regulator no longer increases fuel pressure as the boost comes on. To troubleshoot I pulled off the sensing line from the charge tube to the regulator and connected it to a regulated shop air supply. By adjusting the regulator I could then manipulate the injection pressure as you would expect (2:1 gain). I also noticed the AFR would drop from 13:1 to 11.5:1 as I increased the pressure with the machine idling.. Sounds good right?? Well hooked it back up to the charge tube and took it for a spin to find the same issue fuel pressure stuck at 40psi regardless of boost pressure.. Now I'm wondering if my plumbing is correct..

Plumbing before:
Standard PL stage 3. Fuel tank to fuel pump to TEE fitting supplying both the rising rate regulator and fuel rail. Regulator returns to the tank.

Plumbing now:
Fuel tank to fuel pump to injection rail through rail to regulator and back to the tank.

Regulator is a 2:1 FZ1 Power Valve whatever that is supplied with the PL kit. Did I do something wrong?? The regulator senses from the charge tube, and all my other boxes and guages sense from the intercooler.. Boost was approx 10psi while testing.

Thoughts?? Thanks in advance. Seanny

 

[Ironmanstl]

I'm trying to track down a lean problem as well after installing the return kit with the PL regulator
http://www.ty4stroke.com/viewtopic.php?t=94350

I have my regulator plumbed to the intercooler, but it shouldn't make too much of a difference.
After install, my regulator no longer read my previous 47 lbs at idle but read 60 lbs, so I turned it back down to 47 lbs ( still don't understand why I had to turn it down after the replumb...)
I don't know if the regulator is the problem, but my issues started when I replumbed the rail.

 

[seano700]

Could have the same problem. Mine runs lean now too, but of course if the regulator doesn't increase fuel pressure as the boost comes on problem found now how to correct. To get by for the day I added 12points of fuel to the map and that brought me down to 12.2:1.

Do you have the instructions from the FZ1 regulator? I'm going to do a little research on suggested plumbing for this particular regulator.

 

[seano700]

Does your regulator sense from a line common to your boost guage? Ie are you certain the regulator see's boost? When I connected my reg to shop air it worked fine..

 

[seano700]

Update

After further testing with extra guages and a new regulated supply i found the regulator only putting out 1:1 instead of 2:1 at idle when pressure was applied. I also found the fuel pressure to slightly drop off as i brought the rpm/boost up on a jack stand (although its really hard to build and maintain boost on a stand) When sensing from the charge tube. Anyway long story longer, I took the fuel pressure regulator entirely apart for inspection. Found nothing out of the ordinary, re-installed and voila 2:1 gain is back! Going to take it out on the snow again tomorrow.

 

[Ironmanstl]

Hope it works for you
I spent a long time on the phone with Dave from PL today.
We tried many things to get more fuel on the top end. No success. Only time I seen good a/f was when I set my pressure to 60lbs so I'm seriously thinking problem may be the regulator.
I'm temp relocating my fuel pressure gauge to my bars so
I can see my pressure when pushing 10 lbs

 

[Ironmanstl]

Well
I just pumped 10 lbs of regulated air into the regulator while the sled was running(I teed into the boost gauge to ensure it was accurate), my fuel pressure went from 48 to 59. Definitely not 2:1 ratio. That explains when I set my idle pressure to 60lbs and went for a ride the pressure probably jumped to 70ish and my A/F was perfect. Need to find a good 2:1 regulator now.
Any suggestions?