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 > Engine Tech

Engine Tech Technical discussion related to all relevant engines such as KA, SR, RB, CA, 2JZ , L24/26/28, VG, VQ, and LSx series.


Reply
 
Thread Tools Display Modes
Old 01-10-2016, 06:54 PM   #1
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Sr20det extremely lean all of a sudden

Hey guys my sr20det redtop in a s13 hatch has been running extremely lean out of no where it slowly got there. My afr gauge used to be at the 14-15 range then it went to the 16-17 range and just today went to 19 and 20 the gauge even saids lean once a while now. When i boost it, it runs fine it will boost away no problem. I thought it may have been a boost or vac leak some where cant seem to find any. And i just had new plugs gapped to .32. Ive got a supra twin turbo fuel pump 390lph and i have 750 cc nismo injectors. My fuel pressure is set to 40 psi. Im also running a fuel management system so no iacv. Need help anything works! Thanks!!

I forgot to say it was only at idle it leans out. It will go from 14 ish and then all the way down to 17-19
Rocketbunny240sx is offline   Reply With Quote
Sponsored Links
Old 01-10-2016, 07:41 PM   #2
blksylv
Premium Member
 
blksylv's Avatar
 
Join Date: Nov 2007
Location: bumfuck VA
Posts: 1,814
Trader Rating: (33)
blksylv is not welcome here anymoreblksylv is not welcome here anymoreblksylv is not welcome here anymoreblksylv is not welcome here anymoreblksylv is not welcome here anymoreblksylv is not welcome here anymoreblksylv is not welcome here anymoreblksylv is not welcome here anymoreblksylv is not welcome here anymore
Feedback Score: 33 reviews
any exhaust leaks?
__________________
Quote:
Originally Posted by ixfxi View Post
there is nothing wrong with enjoying the build. however, we sometimes have to remind ourselves that the build is only one part of the puzzle, and that ultimately - enjoying and driving the car is the number one priority.
blksylv is offline   Reply With Quote
Old 01-10-2016, 07:52 PM   #3
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
I'll check but i didnt hear any
Rocketbunny240sx is offline   Reply With Quote
Old 01-10-2016, 09:48 PM   #4
jr_ss
Post Whore!
 
Join Date: Dec 2005
Location: Pa
Posts: 6,054
Trader Rating: (34)
jr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nice
Feedback Score: 34 reviews
Send a message via AIM to jr_ss
Better yet, do you have a tune?

Have you tried a free air calibration for the sensor?
__________________
My SR20VET
jr_ss is offline   Reply With Quote
Old 01-10-2016, 09:49 PM   #5
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Yeah but it has been a while since ive last tuned it. Why would that make it run lean tho? Ecu can reset ?
Rocketbunny240sx is offline   Reply With Quote
Old 01-11-2016, 05:14 PM   #6
Kingtal0n
Post Whore!
 
Kingtal0n's Avatar
 
Join Date: Jul 2005
Location: South Florida
Age: 38
Posts: 4,649
Trader Rating: (17)
Kingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond repute
Feedback Score: 17 reviews
Send a message via AIM to Kingtal0n
walking lean at idle is a sign of bad O2 sensor. disconnect it to diagnose.
Kingtal0n is offline   Reply With Quote
Old 01-11-2016, 05:29 PM   #7
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by Kingtal0n View Post
walking lean at idle is a sign of bad O2 sensor. disconnect it to diagnose.
My car afr gauge runs off the o2 sensor. The o2 is directly connected to the afr gauge and then the gauge is directly connected to me ecu.
Rocketbunny240sx is offline   Reply With Quote
Old 01-12-2016, 12:49 PM   #8
Kingtal0n
Post Whore!
 
Kingtal0n's Avatar
 
Join Date: Jul 2005
Location: South Florida
Age: 38
Posts: 4,649
Trader Rating: (17)
Kingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond repute
Feedback Score: 17 reviews
Send a message via AIM to Kingtal0n
Quote:
Originally Posted by Rocketbunny240sx View Post
My car afr gauge runs off the o2 sensor. The o2 is directly connected to the afr gauge and then the gauge is directly connected to me ecu.

I Have no idea what you just said and it only makes me that much more suspicious that this is related to your problem.
__________________
5.3/4l80e/turbo 240sx playthrough:
https://tinyurl.com/turbo240
Kingtal0n is offline   Reply With Quote
Old 01-12-2016, 04:51 PM   #9
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by Kingtal0n View Post
I Have no idea what you just said and it only makes me that much more suspicious that this is related to your problem.
Im saying my air and fuel ratio gauge is connected directly to my o2 and my ecu connects to me air fuel ratio gauge. On my air fuel ratio gauge theres 2 wires and ive followed them. And thats what i found
Rocketbunny240sx is offline   Reply With Quote
Old 01-14-2016, 01:23 AM   #10
zurud
Zilvia Junkie
 
Join Date: Aug 2009
Location: evansville, in
Posts: 391
Trader Rating: (4)
zurud is an unknown quantity at this point
Feedback Score: 4 reviews
You need to rephrase your statement. I don't think anybody understood you.
Do you have wideband o2 ?
What is your "fuel management"?
zurud is offline   Reply With Quote
Old 01-14-2016, 09:20 AM   #11
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by zurud View Post
You need to rephrase your statement. I don't think anybody understood you.
Do you have wideband o2 ?
What is your "fuel management"?
Fuel management system basically my ecu is trying to idle on its own without a iacv so that has been completely taken out. It uses the mad and o2 to set the car at the lowest possible rating. So that it wont be fricken rich as fk while idling and when boosted it still can deliver super rich fuel. Altho i do have to support it once a while while pulling out of gear or down shifting because it stalls quite easily the idle will sometimes bounce for 1200-2000 and then it will stabilize itself.
Rocketbunny240sx is offline   Reply With Quote
Old 01-14-2016, 07:18 AM   #12
jr_ss
Post Whore!
 
Join Date: Dec 2005
Location: Pa
Posts: 6,054
Trader Rating: (34)
jr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nicejr_ss is just really nice
Feedback Score: 34 reviews
Send a message via AIM to jr_ss
Your AFR gauge has an wideband O2 sensor. If your gauge is hooked to your factory narrow band O2, that is not an accurate means of measuring your O2 reading. If it is indeed a wideband, you should pull it from the exhaust and do a free air calibration on it, if applicable. Your wideband should be connected to the ecu for feedback, so the engine management can see what your AFRs are doing, should your ecu have some type of auto-tune feature.
__________________
My SR20VET
jr_ss is offline   Reply With Quote
Old 01-14-2016, 09:23 AM   #13
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by jr_ss View Post
Your AFR gauge has an wideband O2 sensor. If your gauge is hooked to your factory narrow band O2, that is not an accurate means of measuring your O2 reading. If it is indeed a wideband, you should pull it from the exhaust and do a free air calibration on it, if applicable. Your wideband should be connected to the ecu for feedback, so the engine management can see what your AFRs are doing, should your ecu have some type of auto-tune feature.
I tried to take my o2 sensor out yesterday and ran my car. It richened itself but i didnt try driving with that because i didnt think it was a good idea. Does that mean it was my o2? I tried searching for leaks with carb cleaner and i sprayed it at my hoses like vaccum hoses and all my turbo hoses ect. Idle didnt got up.
Rocketbunny240sx is offline   Reply With Quote
Old 01-14-2016, 10:10 PM   #14
zurud
Zilvia Junkie
 
Join Date: Aug 2009
Location: evansville, in
Posts: 391
Trader Rating: (4)
zurud is an unknown quantity at this point
Feedback Score: 4 reviews
Sorry dude. You are on your own. You mess with your car. Only you know what is going on with it. Nobody pull their IACV. I hope you know what you are doing. Are you trying to be mad scientist or something. ?
zurud is offline   Reply With Quote
Old 01-14-2016, 11:09 PM   #15
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by zurud View Post
Sorry dude. You are on your own. You mess with your car. Only you know what is going on with it. Nobody pull their IACV. I hope you know what you are doing. Are you trying to be mad scientist or something. ?
Naw it was made to be a track car but i daily it. I heard it was better to fuel management than iacv apparently makes the car lighter and faster?
Rocketbunny240sx is offline   Reply With Quote
Old 01-16-2016, 08:21 AM   #16
jedi03
Nissanaholic!
 
Join Date: Jul 2008
Location: albuquerque
Posts: 1,786
Trader Rating: (8)
jedi03 is on a distinguished road
Feedback Score: 8 reviews
Lol I have seem several people who pull theirs...my understanding is its supposed to help it warm up...idle air control valve...the 02 per enthalpy will help with economy, I'm gna replace mine today as mine went lean after 2 years of no issues. I halfway suspect bad fuel for me but I will see!
jedi03 is offline   Reply With Quote
Old 01-16-2016, 02:58 PM   #17
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Do you guys think it could be my maf?
Rocketbunny240sx is offline   Reply With Quote
Old 01-16-2016, 05:04 PM   #18
Kingtal0n
Post Whore!
 
Kingtal0n's Avatar
 
Join Date: Jul 2005
Location: South Florida
Age: 38
Posts: 4,649
Trader Rating: (17)
Kingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond repute
Feedback Score: 17 reviews
Send a message via AIM to Kingtal0n
Here is nutshell SOP
1. Install all OEM parts including IACV
2. compression test, boost leak test, tune up: oil/filters/clean the maf/ clean the inlet (wash all plumbing thorough with degreaser and water) wipe everything completely dry before using it again.
3. Disconnect the narrowband oxygen sensor and drive the car. Does it drive normal? You do not need to boost the engine to drive the car normal.
4. Once you see whether the narrowband was fooling the ECU you can replace the O2 sensor, or start changing other parts i.e. maf/ecu/regulator/fuel pump with the fuel pump being next on the list for sudden lean issues besides narrowbands.
Kingtal0n is offline   Reply With Quote
Old 01-16-2016, 05:48 PM   #19
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by Kingtal0n View Post
Here is nutshell SOP
1. Install all OEM parts including IACV
2. compression test, boost leak test, tune up: oil/filters/clean the maf/ clean the inlet (wash all plumbing thorough with degreaser and water) wipe everything completely dry before using it again.
3. Disconnect the narrowband oxygen sensor and drive the car. Does it drive normal? You do not need to boost the engine to drive the car normal.
4. Once you see whether the narrowband was fooling the ECU you can replace the O2 sensor, or start changing other parts i.e. maf/ecu/regulator/fuel pump with the fuel pump being next on the list for sudden lean issues besides narrowbands.
I had my fuel pump changed not more than id say 3-4 months ago ? Im running a supra twinturbo 390lph fuel pump.
Rocketbunny240sx is offline   Reply With Quote
Old 01-17-2016, 11:03 PM   #20
Kingtal0n
Post Whore!
 
Kingtal0n's Avatar
 
Join Date: Jul 2005
Location: South Florida
Age: 38
Posts: 4,649
Trader Rating: (17)
Kingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond reputeKingtal0n has a reputation beyond repute
Feedback Score: 17 reviews
Send a message via AIM to Kingtal0n
Quote:
Originally Posted by Rocketbunny240sx View Post
I had my fuel pump changed not more than id say 3-4 months ago ? Im running a supra twinturbo 390lph fuel pump.
A used 16 year old OEM fuel pump with 150,000 miles on it from the first owner, and 50k on it from a second owner? Or you dropped more money on your fuel pump buying a new one than your engine is worth. Either way, I don't make the rules. It could be fuel leak, a ruptured ancient fuel in the tank that finally popped maybe your re-used 18 year old fuel lines with presumably all this pumping power.
__________________
5.3/4l80e/turbo 240sx playthrough:
https://tinyurl.com/turbo240
Kingtal0n is offline   Reply With Quote
Old 01-17-2016, 11:15 PM   #21
Rocketbunny240sx
Leaky Injector
 
Join Date: Jan 2015
Location: British columbia
Posts: 77
Trader Rating: (0)
Rocketbunny240sx is an unknown quantity at this point
Feedback Score: 0 reviews
Quote:
Originally Posted by Kingtal0n View Post
A used 16 year old OEM fuel pump with 150,000 miles on it from the first owner, and 50k on it from a second owner? Or you dropped more money on your fuel pump buying a new one than your engine is worth. Either way, I don't make the rules. It could be fuel leak, a ruptured ancient fuel in the tank that finally popped maybe your re-used 18 year old fuel lines with presumably all this pumping power.
My fuel lines are all like the russel steel pipes so its a very low chance
Rocketbunny240sx is offline   Reply With Quote
Reply

Bookmarks

Tags
hatchback, lean, redtop, sr20det


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 02:16 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
vB.Sponsors
Copyright © 1998 - 2019, Zilvia.net™