The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Fuel Injector Clinic
Please Support Morrison Fabrication

Running Rich, or Running Lean? Symptoms of both

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

camas90gsx

10+ Year Contributor
234
0
Jul 16, 2011
seaside, Oregon
Hey, I have a 90 gsx turbo with walboro 255, EVO3 16G,heavily ported evo3 manifold and o2 housing, turbo back exhaust (w no cat), 2g maf, punishment fmic and 650cc injectors. I figured that with the injectors, maf and walboro 255 I would be running a little rich, but the last couple days my car makes a little bit of a popping sound from the exhaust, when I let off the accelerator in 3rd and 4th gear (no where near as intense as it was when I was running the exhaust and walboro 255 w 450cc injectors and 2g maf,EVO3 16G) I have been told is a sign of running lean. The car is running amazing and has lots of power and kick, but I need to know what is causing the popping. Would rewiring my walboro make any difference in this? If so, what does that entail?

Also, if I get an air/fuel gauge, is it just a plug it in and go type of thing? Or how does that work exactly? I have an safc 2 im waiting to hook up also. Any help would be great. Thanks
 
With your setup you need an AFPR. (I learned that here). Buy me one too. Anyway, your idle is probably really rich.

Just wondering, do you have problems with CEL coming on at idle?

Rewiring the fuel pump will give you more Liters Per Hour (lph). I see there's a kit for that now. I did it ghetto Radio Shack style.
 
Get a wideband, idk anything about a safc, i have link, get a tuning device, at least a logger, a way to check codes?
 
you are running pig rich, pull your plugs i bet they're black. running rich will cause your car to 'pop' or backfire. as stated get a afpr and something to tune with.:ohdamn:
 
I'm about to install my safc2 right now.Does anyone know if there is a setting on safc that has a/f levels or where i should start with the tune to be conservative?Do i just use negative levels to lower my fuel levels?
 
Thats not a wideband, get a real wideband you can tune off that, gotta spend the money, do it once and right. That thing just blinks, around 200 bucks but its a investment if you serious about tuning, and saving your engine.
 
I understand that it is not a wideband but with my safc hooked up i would rather have a gauge that gives me some sort of an idea than nothing at all and just guessing.Thats why i refuse to run higher than 13lbs of boost even with the fmic,wally 255,and 650's etc..Believe me i have spent a ton on this car already and wont be stopping anytime soon.Thats why i cant afford the wideband right now because of all of the mods i've been purchasing lately,not because i'm cheap.I would like to run as safe as possiblle until my dyno tune in two and a half weeks and this is my daily driver for the next month so i actually am relying on this car as well.
 
Don't guess and don't take chances by listening to any couch tuner, pull the plugs and look.
 
Last edited:
what about the air/fuel gauges they sell at autozone by sunpro do they give me any sort of idea as to whether im running rich or lean?

Get a wideband. The narrowband you get at autozone just monitors what the front o2 is doing in loops. The wideband actually measures the afr and gives it to you in lamens terms.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top