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

ocska04 · 01-08-2009, 06:33 PM

alright so i was gonna do a compression test on my s14 sr today but when i pulled the first spark plug i come to find it with a white tip... now im running 12lbs full 3" exhaust and a walbro 255 fuel pump and stock injectors... but i recently upgraded the fuel pump cause for a while i was running the stock fuel pump and at 12lbs of boost. Now could that have been the reason for them being white

codunc · 01-08-2009, 07:00 PM

You need an aftermarket fuel pressure regulator if you don't already have one.

Monooxide · 01-08-2009, 07:21 PM

I bet your plugs are white because of the stock fuel pump for sure. Stock KA pump or stock SR pump? That seems pretty dangerous on a Stock KA pump. They may be the same? Regardless still risky.

I run a 255 Walbro and ran 1 Bar which trickled to 12.7 PSI at redline. Measuring the AFR at the tailpipe on my car(S14 SR) it was 11.2 around 4000 RPM and leaned out to 12.2 at redline. Tail pipe reading should be a little leaner than downpipe/elbow readings so maybe 11.7 or less at redline? I would say its safe. BTW I was on Stock ECU, Injectors and MAFS. I made 273 WHP, have fun!

How did your compression turn out?

slider2828 · 01-08-2009, 08:40 PM

Dude read man he said he upraded to a Walbro255.... 12PSI on those 10 year old injectors, you are going to get owned... That is about 80%+ of the injectors....

2nd poster made the best most helpful post. Turn up the fuel pressure, might give you another couple of months....

singlecamslam · 01-08-2009, 08:57 PM

Sorry to thread jack, but is it safe to run 7 PSI on a stock sr20 with s15 turbo with stock fuel pump? I heard it is, just making sure.

Monooxide · 01-08-2009, 09:02 PM

Quote:

Originally Posted by slider2828

Dude read man he said he upraded to a Walbro255.... 12PSI on those 10 year old injectors, you are going to get owned... That is about 80%+ of the injectors....

2nd poster made the best most helpful post. Turn up the fuel pressure, might give you another couple of months....

I was 100% fine on that boost and fuel setup.

He said recently though...How recent?

deukalionS14 · 01-09-2009, 09:22 AM

Quote:

Sorry to thread jack, but is it safe to run 7 PSI on a stock sr20 with s15 turbo with stock fuel pump? I heard it is, just making sure

I wouldn't run a SR on a stock fuel pump. i dont see it being a big issue as long as you dont go balls out all the time...but the FPR is a good idea. just get a Walrbo, Z32, etc fuel pump. that was my 1st upgrade

singlecamslam · 01-09-2009, 09:58 AM

Yea my car is a daily driver for now and once a month i go to an event. I have no trouble with the car, i'm just making sure. I'm getting a Z32TT fuel pump and FPR soon. Thanks.

JRas · 01-09-2009, 11:36 AM

my spark plugs are the same.. except on a stock KA

replaced fuel filter with 300zx

we'll see how the new spark plugs come out...

01-08-2009, 06:33 PM	#1
ocska04 Zilvia Member Join Date: Mar 2005 Location: L.A Posts: 151 Trader Rating: (0) Feedback Score: 0 reviews	Running Lean alright so i was gonna do a compression test on my s14 sr today but when i pulled the first spark plug i come to find it with a white tip... now im running 12lbs full 3" exhaust and a walbro 255 fuel pump and stock injectors... but i recently upgraded the fuel pump cause for a while i was running the stock fuel pump and at 12lbs of boost. Now could that have been the reason for them being white

01-08-2009, 08:40 PM	#4
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 6,040 Trader Rating: (13) Feedback Score: 13 reviews	Dude read man he said he upraded to a Walbro255.... 12PSI on those 10 year old injectors, you are going to get owned... That is about 80%+ of the injectors.... 2nd poster made the best most helpful post. Turn up the fuel pressure, might give you another couple of months.... __________________ Turn and Burn!

01-08-2009, 08:57 PM	#5
singlecamslam Post Whore! Join Date: Apr 2008 Location: Norcal Posts: 2,534 Trader Rating: (10) Feedback Score: 10 reviews	Sorry to thread jack, but is it safe to run 7 PSI on a stock sr20 with s15 turbo with stock fuel pump? I heard it is, just making sure. __________________ Nothing says racecar like a stock car with no interior.

01-09-2009, 09:58 AM	#8
singlecamslam Post Whore! Join Date: Apr 2008 Location: Norcal Posts: 2,534 Trader Rating: (10) Feedback Score: 10 reviews	Yea my car is a daily driver for now and once a month i go to an event. I have no trouble with the car, i'm just making sure. I'm getting a Z32TT fuel pump and FPR soon. Thanks. __________________ Nothing says racecar like a stock car with no interior.

01-09-2009, 11:36 AM	#9
JRas Zilvia FREAK! Join Date: Jul 2007 Location: Arizona Age: 36 Posts: 1,503 Trader Rating: (2) Feedback Score: 2 reviews	my spark plugs are the same.. except on a stock KA replaced fuel filter with 300zx we'll see how the new spark plugs come out... __________________

01-08-2009, 07:00 PM	#2
codunc Zilvia Junkie Join Date: Sep 2006 Location: Denver, CO Age: 35 Posts: 316 Trader Rating: (2) Feedback Score: 2 reviews	You need an aftermarket fuel pressure regulator if you don't already have one.

01-08-2009, 07:21 PM	#3
Monooxide Zilvia Addict Join Date: Mar 2005 Location: Farmington/Flint, MI Age: 37 Posts: 675 Trader Rating: (8) Feedback Score: 8 reviews	I bet your plugs are white because of the stock fuel pump for sure. Stock KA pump or stock SR pump? That seems pretty dangerous on a Stock KA pump. They may be the same? Regardless still risky. I run a 255 Walbro and ran 1 Bar which trickled to 12.7 PSI at redline. Measuring the AFR at the tailpipe on my car(S14 SR) it was 11.2 around 4000 RPM and leaned out to 12.2 at redline. Tail pipe reading should be a little leaner than downpipe/elbow readings so maybe 11.7 or less at redline? I would say its safe. BTW I was on Stock ECU, Injectors and MAFS. I made 273 WHP, have fun! How did your compression turn out?