Turbonetics fuel pump assembly mod
#22
You should only run lean if you're running a reflash. That's why theres such a small margin for error on turbonetics kits equipped with the reflash. Variations in the modification to the bucket assy will cause the car to run lean or rich if it's not drilled out to the precise specifications in the instructions because variations in fuel pressure cannot be fully adjusted for by the stock ECU.
However, if you're running a tunable EMS you should be able to compensate for this via tuning...
However, if you're running a tunable EMS you should be able to compensate for this via tuning...
#24
Originally Posted by Everybodywildou
I have a GSS317 and didnt modify the stock assembly at all. I am running the stock injectors and won't be running the FMU. Will I run lean? Should I use the FMU with the fuel pump?
#25
fmu
Originally Posted by eez
maybe your's is 80 because you have the walbro and FMU (with aux)
#26
Originally Posted by jpc350z
No, the FMU only allows flow to the Aux Fuel pump under boost..My 80 psi is the starting pressure and the pressure goes up from there when the FMU/Aux kicks in...At idle it's 80 psi...
#27
Originally Posted by ZU L8R
Then you need to fix it, it should be @ 51 psi as Charles stated
#28
Originally Posted by jpc350z
No, the FMU only allows flow to the Aux Fuel pump under boost..My 80 psi is the starting pressure and the pressure goes up from there when the FMU/Aux kicks in...At idle it's 80 psi...
#29
there is no fuel flowing the the FMU before the aux pump kicks on. Typically in most installation, there is, however, take a special look at the way in which its installed via the vortech directions on a returnless car.
#30
Originally Posted by phunk
there is no fuel flowing the the FMU before the aux pump kicks on. Typically in most installation, there is, however, take a special look at the way in which its installed via the vortech directions on a returnless car.
Do you actually know how the FMU works???
Let me explain... Fuel flows through the FMU until boost is seen on the MAF. As boost pressure increases it causes this rubber bladder to close the valve and route fuel directly through the AUX pump, which at this time is turned on and pumping.
BTW unless the pump is on, no fuel can actually flow through it. I have studied this setup and dissected it because of the problems I have had.
so...prove me wrong.
oh here is a diagram for you
#32
Fuel does not flow thru the FMU until the Pressure line connected to it sees manifold pressure.(Believe a diaghram inside the FMU). Look at the install instructions and you'll see the line...Its Boost pressure sensed here that allows fuel to flow coupled with an electrical signal from the SS box to the Aux pump that allows a pressure increase of fuel to the rails..
I just noticed your schematic has a 5/32 vent hose that my set does not have...Interesting.. A difference between on 04 and 06 model's..
I just noticed your schematic has a 5/32 vent hose that my set does not have...Interesting.. A difference between on 04 and 06 model's..
Last edited by jpc350z; 12-05-2007 at 04:27 AM.
#33
rather than explain this, ill just point out that if the FMU was a restriction in your flow, as you suggest with your red arrows.... why would you see a spike in a fuel pressure?
#34
Originally Posted by phunk
rather than explain this, ill just point out that if the FMU was a restriction in your flow, as you suggest with your red arrows.... why would you see a spike in a fuel pressure?
Last edited by eez; 12-05-2007 at 05:33 AM.
#36
oh BTW, if the FMU was restricting flow, you would see a pressure drop, not a pressure spike, unless you are reading your fuel pressure at the wrong spot. A pressure spike would only be seen if there was restriction in a return side after a regulator. This is all if we are pretending that fuel were to flow thru the FMU during vacuum anyway.
Last edited by phunk; 12-05-2007 at 05:45 AM.
#37
Originally Posted by phunk
oh BTW, if the FMU was restricting flow, you would see a pressure drop, not a pressure spike, unless you are reading your fuel pressure at the wrong spot. A pressure spike would only be seen if there was restriction in a return side after a regulator. This is all if we are pretending that fuel were to flow thru the FMU during vacuum anyway.