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

757coupe · 01-05-2009, 08:19 AM

..........

Sleepy240 · 01-05-2009, 08:22 AM

Quote:

Originally Posted by 757coupe

Sr20 blacktop (freshly swapped)
fmic, walbro fuel pump, full 3in exhaust (test pipe), stock injectors, untuned

Problem- I can push the car full boost threw 1st and 2nd gear but when i hit full boost in 3rd gear and above the car backfires. Its a couple of small backfires in a row. Car runs great otherwise.

-already reset timing
-have not opened up ecu
-dont know how to check ecu for codes, my blacktop ecu has no lcd light
-the only thing i can assume is a boost leak?

Has anybody had the same problem, advice would be appreciated

You said it yourself, "untuned". Besides that fact my guess would be your running a non-recirc'd BOV which will not help your condition. My suggestion would be get it tuned #1 because your probably running rich in more than one instance

Quote:

Zilvian fags your not worth my time gtfo

you might want to edit this before you end up pinked...

smelly240 · 01-05-2009, 08:22 AM

boost leak prolly, what plugs? stock boost? tuning on a stock car shouldnt be the problem. I never EVER heard of a car breaking up because of it having a fmic and exh oh and a pump.
whats ur plugs gap?

prolly wont be codes.

Sleepy240 · 01-05-2009, 08:40 AM

im willing to bet hes not running stock boost...

if it was a boost leak he would be most likely experiencing those issues in other gears also not just 3rd IMO

757coupe · 01-05-2009, 09:10 AM

..........

supportTHEezln · 01-05-2009, 09:13 AM

Well, if you are running a non-recirculated BOV, a test pipe, and it's untuned, all of those could be your problem.

Sleepy240 · 01-05-2009, 09:19 AM

Quote:

Originally Posted by 757coupe

im running ngk iridiums, there still pregapped cause i dont know what the proper gap is for the sr ( can some fill that in). i know im not runnin to much boost cause my friend has ridden in my car which im hoping is runing about 7lbs and another sr, same set-up on 14lbs and he said he can tell a difference. i dont have any guages or a boost controller yet so i dont know too much about how the motor is runing yet. thanks for your advice guys keep it coming.

With your mods your probably running more than 7, probably closer to 9-10lbs. Also you have no way to monitor how your engine is doing, like I said earlier i'm 99.9999% sure your problem is going to be with running rich. And the problem probably lies any of the issues mentioned earlier... And as the above poster stated, he has the same feelings as I did in my earlier post.

*fliprayzin240sx* · 01-05-2009, 09:25 AM

Gap the plugs down to .028-.030. If your not sure how much boost your running, your running straight off the stock wastegate right? That should be roughly 7 psi. If your running stock boost, stock injectors, the tune shouldnt matter much. You said your running NGK plugs, whats the heat range on them, better yet, just tell us what it is exactly.

757coupe · 01-05-2009, 09:39 AM

Quote:

Originally Posted by fliprayzin240sx

Gap the plugs down to .028-.030. If your not sure how much boost your running, your running straight off the stock wastegate right? That should be roughly 7 psi. If your running stock boost, stock injectors, the tune shouldnt matter much. You said your running NGK plugs, whats the heat range on them, better yet, just tell us what it is exactly.

heat range is six, imma have to get back to you on the gap i cant check them right now.

smelly240 · 01-06-2009, 07:53 AM

Get rid of those super stupid expensive iridiums now and go get some 10$ a set plugs (bkr6es or bkr7es)

.28-.30 for the gap always - and see if it still does it. If so - do a boost leak test (unlike what sleepy says - it can show the effects of the leak only in higher gears where theres more load/volume of air - theres significantly less airflow in 1st/2nd gears than in 3rd and up - and the maps on a stock sr get way richer up there than in the earlier (lower load) parts of the map)

01-05-2009, 08:22 AM	#3
smelly240 Nissanaholic! Join Date: Oct 2006 Location: Philaburbia Age: 43 Posts: 2,137 Trader Rating: (4) Feedback Score: 4 reviews	boost leak prolly, what plugs? stock boost? tuning on a stock car shouldnt be the problem. I never EVER heard of a car breaking up because of it having a fmic and exh oh and a pump. whats ur plugs gap? prolly wont be codes. __________________ HREs on a S13 - check, 6262 - check, Girlfriend.... - nope

01-05-2009, 09:10 AM	#5
757coupe Leaky Injector Join Date: Sep 2007 Location: VA Posts: 90 Trader Rating: (2) Feedback Score: 2 reviews	.......... Last edited by 757coupe; 10-25-2019 at 08:11 AM..

01-05-2009, 09:25 AM	#8
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	Gap the plugs down to .028-.030. If your not sure how much boost your running, your running straight off the stock wastegate right? That should be roughly 7 psi. If your running stock boost, stock injectors, the tune shouldnt matter much. You said your running NGK plugs, whats the heat range on them, better yet, just tell us what it is exactly. __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

01-06-2009, 07:53 AM	#10
smelly240 Nissanaholic! Join Date: Oct 2006 Location: Philaburbia Age: 43 Posts: 2,137 Trader Rating: (4) Feedback Score: 4 reviews	Get rid of those super stupid expensive iridiums now and go get some 10$ a set plugs (bkr6es or bkr7es) .28-.30 for the gap always - and see if it still does it. If so - do a boost leak test (unlike what sleepy says - it can show the effects of the leak only in higher gears where theres more load/volume of air - theres significantly less airflow in 1st/2nd gears than in 3rd and up - and the maps on a stock sr get way richer up there than in the earlier (lower load) parts of the map) __________________ HREs on a S13 - check, 6262 - check, Girlfriend.... - nope

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01-05-2009, 08:19 AM	#1
757coupe Leaky Injector Join Date: Sep 2007 Location: VA Posts: 90 Trader Rating: (2) Feedback Score: 2 reviews	Sr Backfireing WTFFFFF .......... Last edited by 757coupe; 10-25-2019 at 07:41 AM..

01-05-2009, 08:40 AM	#4
Sleepy240 Zilvia Addict Join Date: Sep 2005 Location: Reading, PA Age: 35 Posts: 780 Trader Rating: (0) Feedback Score: 0 reviews	im willing to bet hes not running stock boost... if it was a boost leak he would be most likely experiencing those issues in other gears also not just 3rd IMO

01-05-2009, 09:13 AM	#6
supportTHEezln Zilvia Junkie Join Date: Aug 2004 Location: Los Angeles Age: 36 Posts: 552 Trader Rating: (10) Feedback Score: 10 reviews	Well, if you are running a non-recirculated BOV, a test pipe, and it's untuned, all of those could be your problem.