I just bought a gauge, and its reading 50lbs at idle. And my A/F gauge is almost always in the lean area. These are my engine mods, I/H/E, JRSC @ 10psi, boost upgrade, MSD ignition. What psi do you think I should be running at, at idle. And how do I adjust the psi with the JR FPR?
gmoore

 

Stock idle should be around 33-35psi.

 

But we need to compensate for the mods. So im running an extra 20 psi and my A/F gauge is still reading lean? What should I do?
gmoore

 

Anyone?

 

^^^ Thats one badass site. Thanks!
gmoore

 

Greg can definitely help you out...hes been through a lot with the SC.

Have you tried Hostboard as well? The guys there can teach you a LOT about JRSC's.

http://www.hostboard.com/cgi-bin/ult...bb=forum&f=110

 

What fuel pump are you using? And, are you using any inline's?

The JR FMU is a boost-dependent rising-rate unit. I'm hoping and guessing that you have it.

I must strongly emphasize that higher fuel rail pressures will exceed the stock fuel pump's capacity and possibly damage the injectors. Greg briefly mentions both below.

This is the reason why I ask what I ask: (Taken straight outta his mouth.)
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Get the HO pump. I wish I had.

The 6psi JRSC kit requires fuel pressures that range from 56psi idle to 100+psi at WOT to maintain a rich and safe mix. The JR Fuel Pressure riser that comes with the kits will do this.

The regular pressure pump puts up with this for short periods of time, i.e. drag racing, autocross, street driving. But it will not last as long as normal (normal being 100K + miles) and will run out of steam during extended WOT conditions, causing your mixture to get leaner and leaner. This would be road racing or trying to hit redline in fifth gear type of stuff.

The best thing about the HO pump, besides it was made for the high pressures, is that you may be able to adjust the FPR to keep pressures lower while still keeping a rich mix. This will keep your injectors and fuel lines healthy for longer.
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The last paragraph does kinda strike me as odd reasoning tho. There are only two ways to meter fuel into the cylinders....pressure and injector pw duration. The fuel pump only serves to provide sufficient fuel rail pressure, not to directly affect/feed fuel into the cylinders. Altho, it can indirectly increase fuel rail pressure through increased volume pumpage (interesting wordage?). 100psi of pressure is still 100psi of pressure regardless of fuel pump flow volume....it's a matter of whether it can sustain that pressure through sufficient volume that's the difference.

Or, am I totally off base? Just trying to cover my *** if I start to look totally dumb.


[Modified by IN VTEC, 1:55 AM 2/4/2003]

 

Good stuff, but I have the boost upgrade, which comes with a pump and the JR FPR. Also, this just struck me, the T-bolt that goes into the filter has a hole leading from down in the filter to the line that goes to the rail. I think I may not have this hole lined up, that would affect it also wouldnt it? This just happened, it was running fine before I messed with it, figures. So I know its something I did, and Im guessing thats it.
gmoore