S15 SR20 problem - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

soulsynchromachine · 02-13-2009, 05:47 PM

I just resently did this swap, motor was square decked head resurfaced, crank turned and polished, new bearing arp bolts apexi head gasket, and ssqv with front mount.

It runs good until you get on it. It will pull (kinda hard) then at 5k it will pull even harder

. And then it will also backfire. It has stock injectors and turbo, just hks hi power exhaust. Any ideas?

rioredstang · 02-13-2009, 06:13 PM

I don't know a lot about turbo's but backfiring at high rpm sounds like a lean condition. You need to get someone to hook up a scanner and what O2 sensor and see if its leaning out. You also need to watch map voltage. Backfiring will kill map sensors. Its a good start but need more info to tell much more.

soulsynchromachine · 02-13-2009, 06:18 PM

Right now i have the stock o2 sensor in it now. When i hooked up the scaner it threw no codes. It wont anly backfire at high rpms. It will backfire when i shift at 2500 or 3k.

wrxn240 · 02-13-2009, 06:38 PM

Do you have a boost guage? Does it feel like it's just building more boost? These problems seem quite normal and might not even be considered problems...

WoolyS14DET · 02-13-2009, 06:47 PM

Are you sure you cam timming is correct and it didn't jump a tooth ??
Also are you sure that your CAS is installed correctly ??
Hook a timming light up to it and see what is at.

soulsynchromachine · 02-13-2009, 07:05 PM

Well i have some crappy boost guage, Greddy in transit awaitin it, But the gauge will read fine. I think the timing is right. I hooked up timing light and it was perfect at about 16-17 degrees. It feels as though it should pull all the way through as it pulls at 5k. i also have some compressor surge. Even not under boost.

*fliprayzin240sx* · 02-13-2009, 07:43 PM

How much boost you running? Also, what fuel pump and sparkplugs?

soulsynchromachine · 02-13-2009, 07:54 PM

Ngk spark plugs and a walbro 255. Boost is running at bout 7 psi.

02-13-2009, 05:47 PM	#1
soulsynchromachine Join Date: Jan 2007 Location: ATL GA Posts: 34 Trader Rating: (1) Feedback Score: 1 reviews	S15 SR20 problem I just resently did this swap, motor was square decked head resurfaced, crank turned and polished, new bearing arp bolts apexi head gasket, and ssqv with front mount. It runs good until you get on it. It will pull (kinda hard) then at 5k it will pull even harder . And then it will also backfire. It has stock injectors and turbo, just hks hi power exhaust. Any ideas?

02-13-2009, 06:13 PM	#2
rioredstang Leaky Injector Join Date: Jan 2009 Location: Chattanooga, TN Age: 68 Posts: 81 Trader Rating: (1) Feedback Score: 1 reviews	backfiring I don't know a lot about turbo's but backfiring at high rpm sounds like a lean condition. You need to get someone to hook up a scanner and what O2 sensor and see if its leaning out. You also need to watch map voltage. Backfiring will kill map sensors. Its a good start but need more info to tell much more.

02-13-2009, 07:43 PM	#7
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	How much boost you running? Also, what fuel pump and sparkplugs? __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

02-13-2009, 06:18 PM	#3
soulsynchromachine Join Date: Jan 2007 Location: ATL GA Posts: 34 Trader Rating: (1) Feedback Score: 1 reviews	Right now i have the stock o2 sensor in it now. When i hooked up the scaner it threw no codes. It wont anly backfire at high rpms. It will backfire when i shift at 2500 or 3k.

02-13-2009, 06:38 PM	#4
wrxn240 Leaky Injector Join Date: Aug 2008 Location: Sherman Oaks Posts: 103 Trader Rating: (0) Feedback Score: 0 reviews	Do you have a boost guage? Does it feel like it's just building more boost? These problems seem quite normal and might not even be considered problems...

02-13-2009, 06:47 PM	#5
WoolyS14DET Zilvia FREAK! Join Date: Mar 2008 Location: Long Island, NY Age: 46 Posts: 1,310 Trader Rating: (18) Feedback Score: 18 reviews	Are you sure you cam timming is correct and it didn't jump a tooth ?? Also are you sure that your CAS is installed correctly ?? Hook a timming light up to it and see what is at.

02-13-2009, 07:05 PM	#6
soulsynchromachine Join Date: Jan 2007 Location: ATL GA Posts: 34 Trader Rating: (1) Feedback Score: 1 reviews	Well i have some crappy boost guage, Greddy in transit awaitin it, But the gauge will read fine. I think the timing is right. I hooked up timing light and it was perfect at about 16-17 degrees. It feels as though it should pull all the way through as it pulls at 5k. i also have some compressor surge. Even not under boost.

02-13-2009, 07:54 PM	#8
soulsynchromachine Join Date: Jan 2007 Location: ATL GA Posts: 34 Trader Rating: (1) Feedback Score: 1 reviews	Ngk spark plugs and a walbro 255. Boost is running at bout 7 psi.