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

Go Back   Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum > General > Tech Talk

Tech Talk Technical Discussion About The Nissan 240SX and Nissan Z Cars


Reply
 
Thread Tools Display Modes
Old 02-05-2008, 05:55 PM   #1
nicku
Zilvia Junkie
 
Join Date: Aug 2007
Location: St. Cloud, MN
Age: 30
Posts: 545
Trader Rating: (0)
Feedback Score: 0 reviews
the reasons to cause the car running lean??

as the subject, what are the reasons to make the car run lean??
nicku is offline   Reply With Quote
Sponsored Links
Old 02-05-2008, 06:03 PM   #2
NINJASPY
Zilvia FREAK!
 
Join Date: Oct 2007
Location: So-cal Los Angeles 626
Age: 33
Posts: 1,009
Trader Rating: (13)
Feedback Score: 13 reviews
gas and air. honestly your question cant be any more vague.
NINJASPY is offline   Reply With Quote
Old 02-05-2008, 06:11 PM   #3
nicku
Zilvia Junkie
 
Join Date: Aug 2007
Location: St. Cloud, MN
Age: 30
Posts: 545
Trader Rating: (0)
Feedback Score: 0 reviews
i know...i mean what's the reason to cause the car running lean. because my car was running rich before, and couple days ago, i tried to tight up the bov screw, after that now the idle is like low 15 on my wideband. and I did search online, the tightness on the bov screw doesnt not make the car run lean. Only if it is TOO loose, then the car might run rich. So I thought my car was running rich because of the screw was too loose. and actually my car is running lean. My car has stock boost 7psi, stock injectors 370cc and stock maf. Its a SR redtop. right now, I tried to adjust by the safc so the car doesnt run lean anymore. But im just wondering why everything is stock but the car is lean??
nicku is offline   Reply With Quote
Old 02-05-2008, 06:38 PM   #4
louisdaboois
Zilvia Addict
 
louisdaboois's Avatar
 
Join Date: Dec 2006
Location: LA, CA
Age: 26
Posts: 743
Trader Rating: (16)
Feedback Score: 16 reviews
you can check the bolts and gasket to the turbo elbow... also if the downpipe is properly secured. cause a little exhaust leak in those 2 joints can effect the reading of the o2 sensor by alot.
louisdaboois is offline   Reply With Quote
Old 02-05-2008, 06:49 PM   #5
EAT Motorsports
Zilvia Member
 
EAT Motorsports's Avatar
 
Join Date: Oct 2007
Location: Kirkland, WA
Age: 8
Posts: 242
Trader Rating: (5)
Feedback Score: 5 reviews
Send a message via AIM to EAT Motorsports
exhaust leaks can cause lean reading because of air entering the exhaust stream... anyways...are you lean under acceleration is the real question... 15 at idle is fine/ normal.... do you want to use all your gas idling?
__________________

EAT Motorsports is offline   Reply With Quote
Old 02-05-2008, 06:58 PM   #6
nicku
Zilvia Junkie
 
Join Date: Aug 2007
Location: St. Cloud, MN
Age: 30
Posts: 545
Trader Rating: (0)
Feedback Score: 0 reviews
well...when the car is courising like when I just hold the throttle maintain like 40 miles per hour, the car is like low 15's as well...other than that, when I floor the gas, the car is going like 13s or so. is it normal? how is the car supposed to be actually? I mean during idle, cruising, or flooring the gas. or even just step on the gas a little harder than cruising but not flooring it.
nicku is offline   Reply With Quote
Old 02-05-2008, 07:01 PM   #7
nicku
Zilvia Junkie
 
Join Date: Aug 2007
Location: St. Cloud, MN
Age: 30
Posts: 545
Trader Rating: (0)
Feedback Score: 0 reviews
my another question is.....lets say my exhaust is not leaking. is there any other reason that cause a stock setup running lean?
nicku is offline   Reply With Quote
Old 02-05-2008, 07:10 PM   #8
EAT Motorsports
Zilvia Member
 
EAT Motorsports's Avatar
 
Join Date: Oct 2007
Location: Kirkland, WA
Age: 8
Posts: 242
Trader Rating: (5)
Feedback Score: 5 reviews
Send a message via AIM to EAT Motorsports
vac leak, low fuel flow ( dirty injectors, Fuel Filter), also just asking if you have your narrow band hooked up or what are you doing for that? Also crusing/ idle should be high 14s, wot should be low 13ish.. on a stock ecu, so i think you are doing fine just check over your car for the above....
__________________

EAT Motorsports is offline   Reply With Quote
Old 02-05-2008, 08:01 PM   #9
nicku
Zilvia Junkie
 
Join Date: Aug 2007
Location: St. Cloud, MN
Age: 30
Posts: 545
Trader Rating: (0)
Feedback Score: 0 reviews
i dont have narrow band, i have the plx m300 wideband. well..i have changed to the walbro 255. and im going to pick up 555cc nismo injectors on this weekend. so hopefully, i have time to check over everythign before i install them.
nicku is offline   Reply With Quote
Old 02-05-2008, 09:05 PM   #10
EAT Motorsports
Zilvia Member
 
EAT Motorsports's Avatar
 
Join Date: Oct 2007
Location: Kirkland, WA
Age: 8
Posts: 242
Trader Rating: (5)
Feedback Score: 5 reviews
Send a message via AIM to EAT Motorsports
okay so you have the narrow band output hooked up to your ecu right? good luck also sent you a PM on the injectors.
__________________

EAT Motorsports is offline   Reply With Quote
Old 02-05-2008, 09:30 PM   #11
nicku
Zilvia Junkie
 
Join Date: Aug 2007
Location: St. Cloud, MN
Age: 30
Posts: 545
Trader Rating: (0)
Feedback Score: 0 reviews
yeah the narrow band which is the stock o2 sensor is hooked up to the ecu and the wideband is on the downpipe close to the cat. i believe thats the correct way, right?
nicku is offline   Reply With Quote
Old 02-05-2008, 09:32 PM   #12
EAT Motorsports
Zilvia Member
 
EAT Motorsports's Avatar
 
Join Date: Oct 2007
Location: Kirkland, WA
Age: 8
Posts: 242
Trader Rating: (5)
Feedback Score: 5 reviews
Send a message via AIM to EAT Motorsports
yeah, seems like everything is fine, just double check everything. if its above 13s on stock tune at WOT then you should be worried...
__________________

EAT Motorsports is offline   Reply With Quote
Old 02-05-2008, 10:22 PM   #13
nicku
Zilvia Junkie
 
Join Date: Aug 2007
Location: St. Cloud, MN
Age: 30
Posts: 545
Trader Rating: (0)
Feedback Score: 0 reviews
well...if at wot, the number keeps changing between 13-14....is it okay? by at wot, it means flooring the throttle all the way right? but does it mean all the way to the redline or what? sometimes my wideband reading doesnt read the same. for example, sometimes when im cruising, the reading is like 12 or something. but sometimes is at low 15. and sometimes when i floor the gas a little bit like until 5000 rpm, the number just constantly keeps changing.
nicku is offline   Reply With Quote
Old 02-06-2008, 12:23 AM   #14
nicku
Zilvia Junkie
 
Join Date: Aug 2007
Location: St. Cloud, MN
Age: 30
Posts: 545
Trader Rating: (0)
Feedback Score: 0 reviews
anybody helps???
nicku is offline   Reply With Quote
Old 02-06-2008, 06:51 AM   #15
Omarius Maximus
Zilvia Junkie
 
Join Date: May 2005
Location: San Diego
Posts: 564
Trader Rating: (0)
Feedback Score: 0 reviews
The most common reason for running lean is a vacuum leak. When your just cruising around, the afrs are supposed to be fluctuating because your ecu is in closed loop and constantly adjusting the fuel with the help of your 1st 02 sensor. It's when you floor it that it should stabilize. You want to be at 12.5 or less. Maybe you have a slight vacuum leak, pressure test your system.
Omarius Maximus is offline   Reply With Quote
Old 02-06-2008, 09:22 AM   #16
nicku
Zilvia Junkie
 
Join Date: Aug 2007
Location: St. Cloud, MN
Age: 30
Posts: 545
Trader Rating: (0)
Feedback Score: 0 reviews
oh by the way, i have a s15 t28. but everything else is stock
nicku is offline   Reply With Quote
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 03:39 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
vB.Sponsors
Copyright © 1998 - 2014, Zilvia.net™