So, My install is done, and the car runs pretty good. I am running 5 psi intercooled, and it seems sluggish when I am just cruising. My a/f gauge is like a windshield wiper it just goes back and fourth across the entire guage most of the time. When I boost, it always goes lean, and when I let off it always goes rich. It is only a narrow band guage. Things I think could fix this are:

fuel pump rewire (wally 255lph HP)
new o2 sensor

Oh, and a few notes about my setup- I am using the sfmu, silver spring, 2.72 disc and ring, accell 310cc injectors, it's a 95 with stock fuel return line. My idle fp is at 22 psi (I did not have to adjust it out of the box. It goes up to almost 50 psi at 5 lbs of boost. Oh, and my fuel pressure drops to 0 when I shut off the car, and every time I start it, I have to prime the pump by turning the key 3 times. I will have my egt hooked up in a couple days, that should help too.

Please give me any input or ideas you can think of.
Thanks in advance.

First off, get a WBo2. If the narrow is wiping, at least it's crossing 14.7 so you're in the right range. Under boost, you really need the WB to tell how far rich you are, as you can only guesstimate it. But the combination of 5psi and 310's@50psi is about right, putting you ~180/200hp range (other work depeding).

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'95 GS w/ t3/t4b
FMIC, diy piping & RFL BOV
MS2-Extra Fuel&Spark
50 lb/hr Holley injectors w/ 1:1 RRFPR
JE 8.8:1 dish w/ Hastings Rings
Eagle Rods w/ ARP bolts
ARP Head studs
Mild port/polish head
3" custom DP/cat section, 3" PIT catback
dual MBC - 12 psi / 20psi

Could the o2 sensor be bad? I tapped into the white wire with the black stripe at the ecu. What about the fuel filter? The thing that worries me the most is the no pressure as soon as I shut off the car, and none upon starting either. Where is the pressure going? There are no gas leaks anywhere that I can see or smell. It seems so weird that it would run that good(just a little sluggish while cruising), and get that kind of a/f reading. It is a fast sweeping motion, Like your wipers on HIGH!

read above.. ITS B/C ITS NARROW BAND.

get a wide band..when you boost you go out of the reading range of your narrow band, noting you can do will keep that gauge from sweeping like it does.

Is it possible your pump is just bad? It may loose pressure after shutting it off, as well as not flow the volume required under boost. Your fuel pressure may read 50, but the volume might not be there (I know this sounds strange, but after having it happen on 3 of my 1/2 ton chevy fleet trucks I'm believing it now!) You can have pressure but not volume.

/>

'95 GS w/ t3/t4b
FMIC, diy piping & RFL BOV
MS2-Extra Fuel&Spark
50 lb/hr Holley injectors w/ 1:1 RRFPR
JE 8.8:1 dish w/ Hastings Rings
Eagle Rods w/ ARP bolts
ARP Head studs
Mild port/polish head
3" custom DP/cat section, 3" PIT catback
dual MBC - 12 psi / 20psi

So as far as the a/f reading goes, it will always sweep? It sweeps so fast sometimes that I don't think it could go from rich to lean that fast when I'm not even boosting. If they are all like this, then they are pointless. Because mine tells me nothing. Something has to be up. I've heard nb ones will sweep, but this is pretty extreme!

that's why NB are WORTHLESS. They really have no point, other than to tell you if you O2 sensor is broken or there is some other tragic complication of your motor. The Nerst band is SUPER sensitive around 14.7, which is great for OEM's because of emmissions - but for tuners who work outside the Stoich area they're crap. If you had a stand-alone to read 2 O2 sensors, you could set maps for the NB for cruise/idle and use the WB reading for boosted/accel targets, but 99.9% of us aren't near that lucky.

/>

'95 GS w/ t3/t4b
FMIC, diy piping & RFL BOV
MS2-Extra Fuel&Spark
50 lb/hr Holley injectors w/ 1:1 RRFPR
JE 8.8:1 dish w/ Hastings Rings
Eagle Rods w/ ARP bolts
ARP Head studs
Mild port/polish head
3" custom DP/cat section, 3" PIT catback
dual MBC - 12 psi / 20psi

sell the gauge to some ricer that wants pretty flashing lights and buy yourself a wide band O2. It's the only way that your going to know if your safe or not. A NB gauge can only read from 14.0 to 15.0 AFR if your lucky enough to have a good one. But they're only truly accurate at a perfect stoichiometric AFR (14.7:1). Now when your in boost you want an AFR of 12.5:1 for max power, wich your gauge would read as "burried in rich" but your sensor is probably close enough to the turbo that your overheating the sensor in boost and thats causing it to read "lean" because your motor would have blown by now if you really where leaner than a 15.0:1 afr in boost. let the stock ecu have the NB sensor so you still get good gas mileage when crusing and find your self a WB for tuning. If you cant find one you can afford then at least get an EGT gauge and make sure it never goes above 1600 degrees on pump gas, if its colder your rich and you can lean it a little, if its hotter then you need more fuel.

Creative thinking? Ingenuity? Hell, It's just an obsession!



99 Eclipse GS turbo: MSpowered, everything custom built, 223.8 HP-199.8 TQ @8psi through auto-tranny. The first time around...