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

tibbar650 · 12-12-2006, 12:28 PM

I have a 1995 240sx, it backfires when you let go of the gas, usually at lower rpm's (2-3k) sometimes, but less frequently at higher rpms. I also noticed there is much more significant amount of backfire if OD is on. (its a auto)
I have a GP sports exhaust with 3 inch piping, running on a stock intake. I would like to know if the car is running rich? Or is it just because of the 3 inch piping due to the lack of back pressure. Should i worry about it?

cencal180 · 12-12-2006, 03:45 PM

yea, its fine. my cousin had a gp exhaust on his fastback always poped at 2-3K rpms..my friend has a 95 S14 with an N1 pops at the same rpms. so you should be normal from what i can see. correct me if im wrong.

surge s14 · 12-12-2006, 03:47 PM

mine pops too no worrys man

tibbar650 · 12-12-2006, 03:56 PM

aight thanks, yeah i was a little worried, i had it pop really loud once, so i thought something could be going bad. :0 I bought the exhaust for 50 dollars.

*NemeGuero* · 12-12-2006, 04:46 PM

you're running rich..

exhaust leak possibly..

clutch kick drifter · 12-12-2006, 04:59 PM

if you have a SR, get used to it. Mine back fires in btw every gear and then likeevery time in btw that

, if a Ka, just running rich, check timing.

Replicant_S14 · 12-13-2006, 06:06 AM

Quote:

Originally Posted by NemeGuero

exhaust leak possibly..

Probably. It's hard to get the flanges on 3" stuff to mate with o.e. sized stuff. On top of that, 2 bolt flanges suck anyway.

RalliartRsX · 12-13-2006, 10:55 PM

Probably just running rich from exhaust. From my understanding, with a stock ecu optimised to run with the stock everything, adding a larger diameter, free flowing exhaust will actually have the computer running slightly rich to compensate for the increased flow. Simple fix is to get a fuel pressure regulator.

I have the same problem (signs are incessant backfires and pops regardless of rpms, entire rear end is covered in sooth, crappy MPG, etc.)

I actually find it quiet ammusing as when I drove my car to school every once in while, whilie chugging around campus, it would just do a loud 'pop' and people would drop phones and walk into poles!!! So freaking funny (until I realized I just left about 10 gallons of gas on the back of my car from running rich and and empty wallet

)

smelly240 · 12-12-2006, 05:00 PM

at least ur not shooting 4 foot flames - every now and then i get a good one (one night i blew a oil seal b4 i installed a restrictor - and i shot one that lit up the neighborhood - like WHOA)... most SR guys shoot lots of fire. on a stock car tho - popping is semi normal when u add exhaust. less backpressure so it - naturally - goes outta tune a lil bit.

my one buddy has a ka-t and that thing pops constantly. I dont run a blowoff valve so i dont have the every gear popping stuff.

nsn240 · 12-14-2006, 09:20 AM

Quote:

Originally Posted by smelly240

at least ur not shooting 4 foot flames - every now and then i get a good one (one night i blew a oil seal b4 i installed a restrictor - and i shot one that lit up the neighborhood - like WHOA)... most SR guys shoot lots of fire. on a stock car tho - popping is semi normal when u add exhaust. less backpressure so it - naturally - goes outta tune a lil bit.

4 foot flames for ~6 seconds

(only cause my timing was off though)

backfiring, popping... whatever.. doesnt hurt anything, sounds cool haha

SoSideways · 12-12-2006, 07:56 PM

I get pops between every shift, but no flames.

I used to get flames on the decel (the infamous 1700rpm pop/flame) but I have not gotten anything since I fixed my BOV issues.

How are you guys popping flames still?

smelly240 · 12-12-2006, 11:54 PM

my car does it when it wants i guess... like if i lift and get back on it - maybe its my tip-in? maybe bc i have big injectors? i just know it does it when i drive it hard.

SoSideways · 12-14-2006, 12:14 PM

Well all of my pops happen in between shifts, when the BOV doesn't even open cause I want it that way, so I'd hear compressor surge and a pop.

I think as a matter of fact my car runs lean until I boost and the BOV opens for the first time, then after that it'll run rich.

TPS voltage = 0.37v closed / 4.07 WOT

Timing at 15 degrees BTD per stabbing the CAS according to the FSM.

12-12-2006, 12:28 PM	#1
tibbar650 Join Date: Jul 2006 Location: cali Posts: 9 Trader Rating: (0) Feedback Score: 0 reviews	Backfire I have a 1995 240sx, it backfires when you let go of the gas, usually at lower rpm's (2-3k) sometimes, but less frequently at higher rpms. I also noticed there is much more significant amount of backfire if OD is on. (its a auto) I have a GP sports exhaust with 3 inch piping, running on a stock intake. I would like to know if the car is running rich? Or is it just because of the 3 inch piping due to the lack of back pressure. Should i worry about it?

12-12-2006, 03:47 PM	#3
surge s14 Zilvia FREAK! Join Date: Dec 2005 Location: Laredo Texas Posts: 1,125 Trader Rating: (12) Feedback Score: 12 reviews	mine pops too no worrys man __________________

12-12-2006, 04:46 PM	#5
NemeGuero No more nissan. Join Date: Jan 2003 Location: RAIN, Washington. Age: 40 Posts: 8,132 Trader Rating: (10) Rides Gallery: NemeGuero Feedback Score: 10 reviews	you're running rich.. exhaust leak possibly.. __________________

12-12-2006, 07:56 PM	#11
SoSideways Post Whore! Join Date: Apr 2003 Location: 你老母 Posts: 4,371 Trader Rating: (4) Feedback Score: 4 reviews	I get pops between every shift, but no flames. I used to get flames on the decel (the infamous 1700rpm pop/flame) but I have not gotten anything since I fixed my BOV issues. How are you guys popping flames still? __________________ SoSideway's iTrader Rating!! *SoSideways' Review Thread!!* http://sosideways.wordpress.com/

12-14-2006, 12:14 PM	#13
SoSideways Post Whore! Join Date: Apr 2003 Location: 你老母 Posts: 4,371 Trader Rating: (4) Feedback Score: 4 reviews	Well all of my pops happen in between shifts, when the BOV doesn't even open cause I want it that way, so I'd hear compressor surge and a pop. I think as a matter of fact my car runs lean until I boost and the BOV opens for the first time, then after that it'll run rich. TPS voltage = 0.37v closed / 4.07 WOT Timing at 15 degrees BTD per stabbing the CAS according to the FSM. __________________ SoSideway's iTrader Rating!! *SoSideways' Review Thread!!* http://sosideways.wordpress.com/

12-12-2006, 03:45 PM	#2
cencal180 Join Date: Sep 2005 Location: salinas,ca Posts: 18 Trader Rating: (0) Feedback Score: 0 reviews	yea, its fine. my cousin had a gp exhaust on his fastback always poped at 2-3K rpms..my friend has a 95 S14 with an N1 pops at the same rpms. so you should be normal from what i can see. correct me if im wrong.

12-12-2006, 03:56 PM	#4
tibbar650 Join Date: Jul 2006 Location: cali Posts: 9 Trader Rating: (0) Feedback Score: 0 reviews	aight thanks, yeah i was a little worried, i had it pop really loud once, so i thought something could be going bad. :0 I bought the exhaust for 50 dollars.

12-12-2006, 04:59 PM	#6
clutch kick drifter Zilvia Junkie Join Date: Jul 2005 Location: TN Posts: 498 Trader Rating: (0) Feedback Score: 0 reviews	if you have a SR, get used to it. Mine back fires in btw every gear and then likeevery time in btw that , if a Ka, just running rich, check timing.

12-13-2006, 10:55 PM	#8
RalliartRsX Post Whore! Join Date: Apr 2006 Location: Maryland Posts: 4,793 Trader Rating: (32) Feedback Score: 32 reviews	Probably just running rich from exhaust. From my understanding, with a stock ecu optimised to run with the stock everything, adding a larger diameter, free flowing exhaust will actually have the computer running slightly rich to compensate for the increased flow. Simple fix is to get a fuel pressure regulator. I have the same problem (signs are incessant backfires and pops regardless of rpms, entire rear end is covered in sooth, crappy MPG, etc.) I actually find it quiet ammusing as when I drove my car to school every once in while, whilie chugging around campus, it would just do a loud 'pop' and people would drop phones and walk into poles!!! So freaking funny (until I realized I just left about 10 gallons of gas on the back of my car from running rich and and empty wallet )

12-12-2006, 05:00 PM	#9
smelly240 Nissanaholic! Join Date: Oct 2006 Location: Philaburbia Age: 47 Posts: 2,137 Trader Rating: (4) Feedback Score: 4 reviews	at least ur not shooting 4 foot flames - every now and then i get a good one (one night i blew a oil seal b4 i installed a restrictor - and i shot one that lit up the neighborhood - like WHOA)... most SR guys shoot lots of fire. on a stock car tho - popping is semi normal when u add exhaust. less backpressure so it - naturally - goes outta tune a lil bit. my one buddy has a ka-t and that thing pops constantly. I dont run a blowoff valve so i dont have the every gear popping stuff.

12-12-2006, 11:54 PM	#12
smelly240 Nissanaholic! Join Date: Oct 2006 Location: Philaburbia Age: 47 Posts: 2,137 Trader Rating: (4) Feedback Score: 4 reviews	my car does it when it wants i guess... like if i lift and get back on it - maybe its my tip-in? maybe bc i have big injectors? i just know it does it when i drive it hard.