geramy

My JRSC was running great, but now it seems to be running really lean. It was fine just after the blower was reinstalled, but after a while it has started to run lean? Does any body have any Idea of what it could be? ??fuel pump?? fuel filter?? ??drop in fuel pressure??

I am looking into getting an in cabin fuel pressure gauge, but for now I dont have one so I cant tell you what my fuel pressure is like, can I adjust the fuel pressure and see if this makes any difference?

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PFI Sleeves, Eagle Rods, Arais pistons, Supertech Valve Springs, Supertech Retainers, JR Supercharger reworked by ENDYN, Ported intake Manifold, Ported "S" tube, Skunk 2 Throttle body, AEM CAI, Hytech Header w/3" collector, Custom 3" Exhaust, Meizer Electric Water pump, Neptune, MSD SCI-L ignition, MSD Blaster 2 coil, walbro 255 fuel pump, AEM fuel rail, 1000cc Precision Injectors, FJO Fuel Injector Driver, auto to manual tranny swap, Quaife LSD, Motor Mount inserts, and a little secret...

 

bkw97lude

A drop in temps will cause it to go lean. Heat = rich, and cold = leaner. A see your in Delaware so that was the first thing I thought of.

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2003 SilverStone 350z Enthusiast Delivered 5/23

I/H/E, Exedy Clutch, Hondata 2b (ALL SOLD)
Jackson Racing Supercharged (SOLD)

schwett

obstruction in supply line leading to low pressure

ill-advised adjustment of the jr fmu

ground or other electrical problem preventing the jr enrichment circuit from doing it's job

fuel pump failure leading to low pressure

broken ring lands, causing the fuel to blow past the pistons and into the crankcase - this is why my car took so much more pressure than it should've with the 370s

much cooler weather or reduced restriction in the intake, head, header


DO NOT screw with fuel pressure without an in-cabin gauge!!!!!!!!!!!!!!!!!!

geramy

Thanks Bkw97lude and Schwett, I think that it may be an obstruction someplace in the fuel line. My fuel gauge stopped working (it wont go any further down than just under half) and I think I may have sucked something up from the bottom of the tank. I am going to replace the filter and see if that helps. If not then I will check out the electrics.

I didnt even think about the change in weather because it started about a week ago and it was still warm here. But that was a good point.

Yeah I didnt want to mess with the fuel pressures until I had a gauge, I dont think I know enough to just go off a guess...

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PFI Sleeves, Eagle Rods, Arais pistons, Supertech Valve Springs, Supertech Retainers, JR Supercharger reworked by ENDYN, Ported intake Manifold, Ported "S" tube, Skunk 2 Throttle body, AEM CAI, Hytech Header w/3" collector, Custom 3" Exhaust, Meizer Electric Water pump, Neptune, MSD SCI-L ignition, MSD Blaster 2 coil, walbro 255 fuel pump, AEM fuel rail, 1000cc Precision Injectors, FJO Fuel Injector Driver, auto to manual tranny swap, Quaife LSD, Motor Mount inserts, and a little secret...

iranman

Out of curiosity, how do you know you're running lean? Or that you were running rich before?

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Sina
My JRSC Site

geramy

Just going by the Air/Fuel gauge, its not perfect or completely accurate but I can also feel the car not pulling or bogging and when I check out the gauge it is way into the "Lean" then it will jump into the "Rich", but just barely and I can feel the power return.
At idle, it used to bounce from "stoich." all the way to the last light in the "rich" now it is almost completely opposite.

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PFI Sleeves, Eagle Rods, Arais pistons, Supertech Valve Springs, Supertech Retainers, JR Supercharger reworked by ENDYN, Ported intake Manifold, Ported "S" tube, Skunk 2 Throttle body, AEM CAI, Hytech Header w/3" collector, Custom 3" Exhaust, Meizer Electric Water pump, Neptune, MSD SCI-L ignition, MSD Blaster 2 coil, walbro 255 fuel pump, AEM fuel rail, 1000cc Precision Injectors, FJO Fuel Injector Driver, auto to manual tranny swap, Quaife LSD, Motor Mount inserts, and a little secret...