sr20 running extremely lean - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

conor14 · 12-24-2012, 05:28 PM

My sr20det redtop was running very lean on a pretty much stock motor. My car ran from 16-18:1 to off the charts

so I installed a 255 walbro and a nismo fpr and its still running very lean. when i first started it it was idling at 12-14:1 and after letting it warm up and giving it some gas it idled at 16 to off the charts

I have an safc 2 ( relax im going into university ) but havent installed it, could I just adjust the fpr to help my leaning out issues? i really thought the new pump was gunna fix this problem.

cotbu · 12-25-2012, 01:02 AM

you just bought into the walbro pump upgrade makes you rich by over powering the fpr, which makes no sense anyway, but that misconception still runs rampant.

you could do a few things, read the plugs and or calibrate your wideband, also check for exhaust leaks before the wideband sensor
reading the plugs: at 18 to 1, i would expect to see super white plugs, maybe even damage from pinging. Which would confirm being extremely lean. Although if that was the case and the knock sensor is functioning???!!! you would be seeing rich afr's and probably even be undriveable.
calibrating the wideband: the sensor maybe worn or just not reading correctly. You could actually be stoich.

normally at idle, you could get away with a lean 16afr and be ok. I've only tuned that lean for 2 guys both were doing tri state cruise. I tweaked timing and fuel in the closed loop portion of the map

12-24-2012, 05:28 PM	#1
conor14 Join Date: Jun 2012 Location: Alberta Age: 30 Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	sr20 running extremely lean My sr20det redtop was running very lean on a pretty much stock motor. My car ran from 16-18:1 to off the charts so I installed a 255 walbro and a nismo fpr and its still running very lean. when i first started it it was idling at 12-14:1 and after letting it warm up and giving it some gas it idled at 16 to off the charts I have an safc 2 ( relax im going into university ) but havent installed it, could I just adjust the fpr to help my leaning out issues? i really thought the new pump was gunna fix this problem. Last edited by conor14; 12-24-2012 at 06:56 PM..

12-25-2012, 01:02 AM	#2
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 50 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	you just bought into the walbro pump upgrade makes you rich by over powering the fpr, which makes no sense anyway, but that misconception still runs rampant. you could do a few things, read the plugs and or calibrate your wideband, also check for exhaust leaks before the wideband sensor reading the plugs: at 18 to 1, i would expect to see super white plugs, maybe even damage from pinging. Which would confirm being extremely lean. Although if that was the case and the knock sensor is functioning???!!! you would be seeing rich afr's and probably even be undriveable. calibrating the wideband: the sensor maybe worn or just not reading correctly. You could actually be stoich. normally at idle, you could get away with a lean 16afr and be ok. I've only tuned that lean for 2 guys both were doing tri state cruise. I tweaked timing and fuel in the closed loop portion of the map __________________ LoverTechnologies "Half Broken Things!"