Fuel PSI issue

[SxLxAxVxExN]

I've got a vortech super fmu and have problems setting the fuel pressure under WOT. At idle she's at around 40-43ish and under boost she goes almost to a 100 psi. On the FMU there's 4 different setting screws: Top is static pressure, and on the side there's boost, vacuum, and bleed. Which one do I adjust the WOT pressure with??
She's running way too rich at WOT i'm seeing mid 10's on the wideband and the FI light tends to come on at times.
Also I don't have a check valve in the line to the FMU yet.. which way is it supposed to go in the line?
Thanks in advance and yes I did try and search but couldn't find the answer I am looking for.

 

[TurboSN95]

isn't there a diaphragm or something inside like a plate that you change? thats what i recall from back in the day when we used fmu's...

 

[cdhoroho]

isn't there a diaphragm or something inside like a plate that you change?  thats what i recall from back in the day when we used fmu's...

this is a vortech super fmu (fully adjustable)





SxLxAxVxExN,
try adjusting the bleed screw out just a bit
only a 1/4 turn at a time

what map are you using
and what boost level
try mapping it down a bit too
90-100 psi is what mine ran (when i ran an fmu)

 

[SxLxAxVxExN]

I tried the bleed screw turning it out actually increases the pressure. So it's pretty much all the way in. The map is set for 6psi of boost and I'm running about 8 cause i thought more boost would kinda lower the A/F but that didn't work either.
from what i read here on the forums don't the injectors tend to lock up at 90+ psi? That's what i am worried about, last thing I wanna do is blow something up lol.

 

[cdhoroho]

mine didnt lock up till the 125 psi range
my pressure spiked to 125 and that caused burn pistons

what is your base pressure?
try dropping it a bit
and then remap the bike for the higher psi
it shouldnt lock up the injectors if you keep the duty cycle down a bit and dont let the pressure spike above where your at now

 

[SxLxAxVxExN]

I turned the base pressure down to about 40 did some adjustments to the bleed valve, the boost and vacuum adjusting screws are turned in all the way. I'll take her for a ride in a few and see if it's any different.
Another thing with the sensors though.. there;s the map sensor, the black vacuum canister thingie and then theres two sensors underneath that canister. All of those sensors dont have vacuum lines going to them. Does this matter?

 

[SxLxAxVxExN]

Well the unexpected happened today.. I went out pulled the bike out of the garage started it up went in the house to get a drink came back out and there's white/blue smoke pouring out of the dump pipe. So I shut her off and a minute later oil started dripping out of the pipe.
So I believe the turbo is shot. I'll take it back up to the shop tomorrow and we'll figure out what the deal is.
better turbo than the motor

 

[cdhoroho]

do you have the crank case vent opened?
it needs to have an opening or it will spew oil


also the map sensor needs the vacuum nothing else (of those sensors)

 

[SxLxAxVxExN]

Map sensor has its own vacuum lines. What exactly do u mean by open crankcase? I'll take some pics tomorrow of how everything is and post em up.. Anyone have pics of their setup so i can compare it to mine?

 

[cdhoroho]

the crank case vent is the large box on the top of the case
if the is blocked it will blow blue/white smoke big time out of the exhaust

 

[SxLxAxVxExN]

Oh crap that might be the problem then, cause I did put a little cap over it cause I didnt want the fuel psi sender grounding on it. I'll go take it off and see what it does.

 

[cdhoroho]

that is why it is smoking
your crank case needs to vent
if you want you can take a hose and run it to the tail of the bike to vent there

 

[SxLxAxVxExN]

Yep that was it. Im an idiot no doubt about it.
So back to the fuel pressure..
i got it to stay around 85 psi at WOT and 5 psi, and the A/F stays at about 10.5-11.0 which is too rich, so I'll try to turn the boost up to about 7 or 8 and that should bring it down some i hope. And if that don't work then I'll go into the map and take some fuel out it.

 

[BrianK]

you are getting close............

 

[SxLxAxVxExN]

you are getting close............

Not quite.. she still needs a ton of tuning. Turned the boost up to about 8 and now the FI light comes on everytime I take her down the street.
Good thing I have the nerves for this crap.

 

[cdhoroho]

that means either your over working your injectors (to high of a duty cycle)
or your letting the map sensor see boost

 

[enemy]

"So back to the fuel pressure..
i got it to stay around 85 psi at WOT and 5 psi, and the A/F stays at about 10.5-11.0  which is too rich, so I'll try to turn the boost up to about 7 or 8 and that should bring it down some i hope."

If you are running an FMU turning the boost up will raise your fuel pressure in proportion to referenced boost I would think? So trying to tune A/F with boost is kind of chasing the tail I think. I would investigate your FMU a bit further to find out why it won't let you bring referenced fuel pressure down into the 60-70 psi range.
Just the 02 of a noob..

Jon

 

[OZBooster]

Jon the FMU doesn't track with fuel needs , sort of like 2 lines intersecting on similar angles, but not quite the same... only correct for a couple of psi after that your compromising rich for low boost and lean for high.

 

[enemy]

Jon the FMU doesn't track with fuel needs , sort of like 2 lines intersecting on similar angles, but not quite the same... only correct for a couple of psi after that your compromising rich for low boost and lean for high.

That makes better sense to me putting it that way! It was explained quite a bit different to me in the past.

 

[rocketgeezer]

Yep that was it. Im an idiot no doubt about it.
So back to the fuel pressure..
i got it to stay around 85 psi at WOT and 5 psi, and the A/F stays at about 10.5-11.0  which is too rich, so I'll try to turn the boost up to about 7 or 8 and that should bring it down some i hope. And if that don't work then I'll go into the map and take some fuel out it.

Are you running the map I sent you? if so you got way to much fuel pres if you got 8psi boost you need to be 70-75 boosted fuel pres, right now I' running that map with 95-100 psi fuel pres but I'm also running 12 lbs boost and in hot weather its still a little rich, also no two bikes are the same so the same map wont work the same, I see your trying to tune it your self with the datalogger thats cool but it takes a while, set your boost where you want it 8 lbs? then set your fuel pres, right now I would say no more than than 70 lbs boosted take your readings if you dont see a good change take out another 10 lbs, if nothing changes or changes very little your going to have to adjust map numbers in the rich places, just once you set a certain boost pres leave it be and adjust for it cause when you change boost pres that changes fuel pres and than you have to stary all over again this is why its a pain in the ass to try to tune this way, you may have to get it on a dyno and have a custom map done that way at least you will have a backup up if you change anything Good Luck Dave