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

ny-s14blacktop · 03-21-2006, 07:30 AM

I have a 96 nissan 240sx in the great state of new york and have the s14 sr20det vvt blacktop engine with a greddy intercooler, greddy bov, greddy boost controller, greddy down pipe , custom 3 inch exaust all the way back and some other stuff but not worth noting. My problem or question is that my car backfires a lot and loud like a gunshot, I stay scaring the shit out of the homies down the blok but I am wondering if this is normal or causing damage, it seems to me like it happens when I get on it then drive normal pop, could this be b/c of my free flowing exaust, and is it hurting my car and how do you fix this

neverlift · 03-21-2006, 07:46 AM

my sohc ka does this sometimes,a friend told me it was detonation or timming,what octane gas do you run?

ryangreg · 03-21-2006, 08:23 AM

Man, its that BOV you have venting to atmosphere. Do a quick search and you'll find plenty of shit.

sr20newb · 03-21-2006, 08:32 AM

Is it only backfiring when you first drive it? or even after it warms up?

aznpoopy · 03-21-2006, 08:39 AM

if you have your bov and maf set up like 99% of people... then yeah. turbo blows air. air is metered. throttle closes, bov opens (goes pssh). the car already injected fuel for that air that never made it into the cylinder. result? car runs rich between shifts and you get a pop or a bang out the exhaust

neverlift · 03-21-2006, 10:49 AM

sorry bout jacking thread,but what about na ka?

ny-s14blacktop · 03-21-2006, 11:17 AM

I run premium and it happens after the throttle was 100%, then I drive normal and then I get a backfire

smithers584 · 03-21-2006, 03:47 PM

what are you using to tune your fuel? have you got your A/F ratio dialed in correctly? if not, you are just running rich, thats all a backfire is usually. maybe one of your sensors is bad and causing it to run rich, maybe you need to tell us more about your car and its history. Its hard to tell you without knowing these types of things and what you have tried to do to troubleshoot it. its definately not due to your "free flowing exhaust".

smithers584 · 03-21-2006, 03:52 PM

Quote:

Originally Posted by aznpoopy

if you have your bov and maf set up like 99% of people... then yeah. turbo blows air. air is metered. throttle closes, bov opens (goes pssh). the car already injected fuel for that air that never made it into the cylinder. result? car runs rich between shifts and you get a pop or a bang out the exhaust

so are you saying it would be more accurate with a blow through MAF located on your cold pipe right before your TB? my buddy went that route, but i havent had any problems and i usually do not hear any backfiring with mine mounted after the filter.

03-21-2006, 07:30 AM	#1
ny-s14blacktop Join Date: Mar 2006 Location: upstate ny Posts: 13 Trader Rating: (0) Feedback Score: 0 reviews	backfire I have a 96 nissan 240sx in the great state of new york and have the s14 sr20det vvt blacktop engine with a greddy intercooler, greddy bov, greddy boost controller, greddy down pipe , custom 3 inch exaust all the way back and some other stuff but not worth noting. My problem or question is that my car backfires a lot and loud like a gunshot, I stay scaring the shit out of the homies down the blok but I am wondering if this is normal or causing damage, it seems to me like it happens when I get on it then drive normal pop, could this be b/c of my free flowing exaust, and is it hurting my car and how do you fix this

03-21-2006, 07:46 AM	#2
neverlift Zilvia Member Join Date: Jan 2006 Location: DUVAL Posts: 166 Trader Rating: (0) Feedback Score: 0 reviews	my sohc ka does this sometimes,a friend told me it was detonation or timming,what octane gas do you run? __________________ derp derp

03-21-2006, 10:49 AM	#6
neverlift Zilvia Member Join Date: Jan 2006 Location: DUVAL Posts: 166 Trader Rating: (0) Feedback Score: 0 reviews	sorry bout jacking thread,but what about na ka? __________________ derp derp

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03-21-2006, 08:23 AM	#3
ryangreg Zilvia Member Join Date: Feb 2006 Location: exeter Posts: 216 Trader Rating: (0) Feedback Score: 0 reviews	Man, its that BOV you have venting to atmosphere. Do a quick search and you'll find plenty of shit.

03-21-2006, 08:32 AM	#4
sr20newb Leaky Injector Join Date: Feb 2006 Location: Santa Rosa, CA Posts: 135 Trader Rating: (0) Feedback Score: 0 reviews	Is it only backfiring when you first drive it? or even after it warms up?

03-21-2006, 08:39 AM	#5
aznpoopy Post Whore! Join Date: Mar 2003 Location: New Jersey Age: 44 Posts: 5,013 Trader Rating: (1) Feedback Score: 1 reviews	if you have your bov and maf set up like 99% of people... then yeah. turbo blows air. air is metered. throttle closes, bov opens (goes pssh). the car already injected fuel for that air that never made it into the cylinder. result? car runs rich between shifts and you get a pop or a bang out the exhaust

03-21-2006, 11:17 AM	#7
ny-s14blacktop Join Date: Mar 2006 Location: upstate ny Posts: 13 Trader Rating: (0) Feedback Score: 0 reviews	I run premium and it happens after the throttle was 100%, then I drive normal and then I get a backfire

03-21-2006, 03:47 PM	#8
smithers584 Zilvia Junkie Join Date: Dec 2004 Location: sc Posts: 416 Trader Rating: (0) Feedback Score: 0 reviews	what are you using to tune your fuel? have you got your A/F ratio dialed in correctly? if not, you are just running rich, thats all a backfire is usually. maybe one of your sensors is bad and causing it to run rich, maybe you need to tell us more about your car and its history. Its hard to tell you without knowing these types of things and what you have tried to do to troubleshoot it. its definately not due to your "free flowing exhaust".