02 sensor question, affect idle? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

ultimateirving · 11-18-2011, 03:53 PM

So ive been running without my o2 sensor plugged in for quite a while(harness wiring is shorted) im tired of bad Economy so i plan to rewire it and hook it up and im wondering if this may help fix my high idle.
I cant get it below 1300 rpms, tried 2 different IACV valves cleaned and set the idle for both iacv per FSM..
Just wondering if hookin it up again will have any impact, other then gas mileage

2.5T_/<ouki · 11-18-2011, 04:04 PM

Just curious how BAD was the fuel economy?

How many miles to a full tank of gas? S13 / S14?

ultimateirving · 11-18-2011, 04:10 PM

converted to e85, went from 25-26mpg.. would fill up at about 250-275 miles.
Now i get like 14-15, im lucky to get to 160miles per tank

I know there is a loss of mileage for E85, but i dont think it would drop that bad, thats like 45% i was thinking id be closer to 18-19 mpg.. i know that even bringing the idle down will help, but i seriously cannot get it any lower. the IACV screw is like in as far as it can go..

chituntang · 11-18-2011, 04:27 PM

Get a wideband and datalog your a/f to see...

ultimateirving · 11-18-2011, 04:39 PM

Quote:

Originally Posted by chituntang

Get a wideband and datalog your a/f to see...

Thats my other problem!! this is from my other thread...

"anyone else running this wideband, i need help. Recently it stopped functioning, i figured maybe a ground came loose or something. SO I rewired the grounds to all the same point, and rewired the 12v ign wire to make sure that was good too. The sensor itself does not warm up when the ign is on, i spent about 2 hours wiring and rewiring trying different locations and i cannot for the life of me get this fixed.

Anyone else experience this issue?"

2.5T_/<ouki · 11-18-2011, 05:42 PM

Sorry i couldn't be of any help. Wanted to see your economy cuz i am having a similar problem running 91! RB25 in S14 and i only get about 160-200 miles to a full tank of gas, however i am running an o2 sensor. Hope you get your issue fixed.

GL!

rcdad123 · 11-19-2011, 02:08 AM

check for vacuum leaks and the throttle stop for your throttle body. hooking up the o2 sensor should lean out the a/f ratio and will likely raise the idle even more.

Walperstyle · 11-19-2011, 03:34 AM

get the Wideband working first. Also, do you have an ECU that needs your wideband to function properly, aka, standalone??

ultimateirving · 11-20-2011, 09:50 PM

Quote:

Originally Posted by Walperstyle

get the Wideband working first. Also, do you have an ECU that needs your wideband to function properly, aka, standalone??

nah, using e5 ecu with rom tune.

11-18-2011, 03:53 PM	#1
ultimateirving Zilvia FREAK! Join Date: Nov 2010 Location: arizona Age: 37 Posts: 1,521 Trader Rating: (1) Feedback Score: 1 reviews	02 sensor question, affect idle? So ive been running without my o2 sensor plugged in for quite a while(harness wiring is shorted) im tired of bad Economy so i plan to rewire it and hook it up and im wondering if this may help fix my high idle. I cant get it below 1300 rpms, tried 2 different IACV valves cleaned and set the idle for both iacv per FSM.. Just wondering if hookin it up again will have any impact, other then gas mileage __________________ Z32 with lq4 swap Desert Street Scene \|\| Dssevents.com

11-18-2011, 04:10 PM	#3
ultimateirving Zilvia FREAK! Join Date: Nov 2010 Location: arizona Age: 37 Posts: 1,521 Trader Rating: (1) Feedback Score: 1 reviews	converted to e85, went from 25-26mpg.. would fill up at about 250-275 miles. Now i get like 14-15, im lucky to get to 160miles per tank I know there is a loss of mileage for E85, but i dont think it would drop that bad, thats like 45% i was thinking id be closer to 18-19 mpg.. i know that even bringing the idle down will help, but i seriously cannot get it any lower. the IACV screw is like in as far as it can go.. __________________ Z32 with lq4 swap Desert Street Scene \|\| Dssevents.com

11-19-2011, 03:34 AM	#8
Walperstyle Nissanaholic! Join Date: Nov 2004 Location: Alberta, Red Derp Age: 44 Posts: 1,729 Trader Rating: (0) Feedback Score: 0 reviews	get the Wideband working first. Also, do you have an ECU that needs your wideband to function properly, aka, standalone?? __________________ KA-T ORG-Function over Flush

11-18-2011, 04:04 PM	#2
2.5T_/<ouki Zilvia FREAK! Join Date: Oct 2011 Location: SoCal Posts: 1,150 Trader Rating: (13) Feedback Score: 13 reviews	Just curious how BAD was the fuel economy? How many miles to a full tank of gas? S13 / S14?

11-18-2011, 04:27 PM	#4
chituntang Zilvia Junkie Join Date: Sep 2005 Location: ATL Age: 38 Posts: 505 Trader Rating: (13) Feedback Score: 13 reviews	Get a wideband and datalog your a/f to see...

11-18-2011, 05:42 PM	#6
2.5T_/<ouki Zilvia FREAK! Join Date: Oct 2011 Location: SoCal Posts: 1,150 Trader Rating: (13) Feedback Score: 13 reviews	Sorry i couldn't be of any help. Wanted to see your economy cuz i am having a similar problem running 91! RB25 in S14 and i only get about 160-200 miles to a full tank of gas, however i am running an o2 sensor. Hope you get your issue fixed. GL!

11-19-2011, 02:08 AM	#7
rcdad123 Zilvia Addict Join Date: Jul 2011 Location: san diego Posts: 639 Trader Rating: (0) Feedback Score: 0 reviews	check for vacuum leaks and the throttle stop for your throttle body. hooking up the o2 sensor should lean out the a/f ratio and will likely raise the idle even more.