Odd richness problem... - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

sunnys14 · 02-13-2008, 10:25 PM

Built KA-T
AFR's are fine while cruising while engine isnt totally warmed up (13.6-14.5). After it reached operating temperature, cruising AFR's go from 11.5-13.9 up and down. At WOT its 11.5 no matter if the engine is cold or warmed up all the way, so it cant be a boost leak. Checked for boost leaks and nothing. Changed the O2 sensor, new CTS, plugs, wires, cap and rotor. Wideband sensor is also fairly new.

Not sure what the problem is... is the the TPS going bad? Car thinks that its WOT sometimes when its not (hence afr's dropping to 11.5 sometimes). But the problem only happens after ive been driving for about 10 minutes. Happens ONLY during cruising and out of boost, WOT is fine (AFR's 11.5 and no bucking). No power loss either...

02-13-2008, 10:25 PM	#1
sunnys14 Zilvia FREAK! Join Date: Mar 2006 Location: a land far far away... Posts: 1,549 Trader Rating: (19) Feedback Score: 19 reviews	Odd richness problem... Built KA-T AFR's are fine while cruising while engine isnt totally warmed up (13.6-14.5). After it reached operating temperature, cruising AFR's go from 11.5-13.9 up and down. At WOT its 11.5 no matter if the engine is cold or warmed up all the way, so it cant be a boost leak. Checked for boost leaks and nothing. Changed the O2 sensor, new CTS, plugs, wires, cap and rotor. Wideband sensor is also fairly new. Not sure what the problem is... is the the TPS going bad? Car thinks that its WOT sometimes when its not (hence afr's dropping to 11.5 sometimes). But the problem only happens after ive been driving for about 10 minutes. Happens ONLY during cruising and out of boost, WOT is fine (AFR's 11.5 and no bucking). No power loss either...