PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Running Lean...how to fix this issue? (tuning newbie)

Thread Tools
 
Search this Thread
 
Old Apr 15, 2003 | 09:32 AM
  #1  
2K2CamaroSS's Avatar
Thread Starter
TECH Apprentice
iTrader: (18)
 
Joined: May 2002
Posts: 323
Likes: 0
From: Aurora, CO
Default Running Lean...how to fix this issue? (tuning newbie)

I found out on from a recent dyno that I'm running lean with my ported and polished MAF ends. Around 14.5:1 A/F ratio that varies through out the RPM range. In the higher RPM range is wear it's the leanest. I was wondering if there was an easy fix to this. Someone had mentioned something uping the fuel pressure by 1 psi.

Anyone have anyideas? I'm a newbie at this tuning stuff

FYI: Before the port and polished MAF ends I was running a constant 12.3:1 A/F

Brian

PS...I'm really loving the extra gas mileage though <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

<small>[ April 15, 2003, 09:37 AM: Message edited by: 2K2CamaroSS ]</small>
Reply
Old Apr 15, 2003 | 09:48 AM
  #2  
killer01ws6's Avatar
TECH Resident
 
Joined: Mar 2003
Posts: 770
Likes: 0
From: Troy Al
Default Re: Running Lean...how to fix this issue? (tuning newbie)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> In the higher RPM range is wear it's the leanest </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Careful those two combinations
can lead to a burned piston....

I would not pound on her or replace the stock ones till you get a good answer on getting more fuel to her... <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
Reply
Old Apr 15, 2003 | 11:26 AM
  #3  
2K2CamaroSS's Avatar
Thread Starter
TECH Apprentice
iTrader: (18)
 
Joined: May 2002
Posts: 323
Likes: 0
From: Aurora, CO
Default Re: Running Lean...how to fix this issue? (tuning newbie)

is 14.5:1 A/F really that dangerous

14.5 is the leanest it gets, which is at 6000 RPMS, the rest of the time it bounces from 14.1-14.3:1

Is that a safe A/F ratio? or Should I get this corrected ASAP...(I had the stock MAF ends ported and polished so I don't have any ones that I can revert to.)
Reply
Old Apr 15, 2003 | 02:44 PM
  #4  
killer01ws6's Avatar
TECH Resident
 
Joined: Mar 2003
Posts: 770
Likes: 0
From: Troy Al
Default Re: Running Lean...how to fix this issue? (tuning newbie)

IMO yes that is to lean and could cause you problems I have read you want to be between
A/F -12.5:1 TO -12.8:1 at peak HP,

again I would baby her till you find out more for sure <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
Reply
Old Apr 15, 2003 | 03:19 PM
  #5  
killer01ws6's Avatar
TECH Resident
 
Joined: Mar 2003
Posts: 770
Likes: 0
From: Troy Al
Default Re: Running Lean...how to fix this issue? (tuning newbie)

OK 2K2CamaroSS, I Would never want to give someone bad info, so I did some research,
The idea is to go as high as you can without knock. So, if you are 12.6(rich) and you would tweak the MAFT until you got 12.7, 12.8 and so on. With each run, you should have an increase in power the leaner you go. You would keep doing this until you detect knock and then back the MAFT down one notch. Typically, 12.8 is the best torque and 13.2 is the best HP
...

SO you want to make sure you are not getting any KR or pinging...

I hope this helps buddy. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
Reply
Old Apr 15, 2003 | 03:33 PM
  #6  
2K2CamaroSS's Avatar
Thread Starter
TECH Apprentice
iTrader: (18)
 
Joined: May 2002
Posts: 323
Likes: 0
From: Aurora, CO
Default Re: Running Lean...how to fix this issue? (tuning newbie)

Excellent info. Thanx

Now what's the difference between the MAFT versions?
Reply
Old Apr 15, 2003 | 03:56 PM
  #7  
killer01ws6's Avatar
TECH Resident
 
Joined: Mar 2003
Posts: 770
Likes: 0
From: Troy Al
Default Re: Running Lean...how to fix this issue? (tuning newbie)

that is an other one of the devices to trick the pcm on what the a\f ratio is. You are not running one,(from your sig) and I think they are for adjusting more lean, so that would take you in the wrong direction
Reply
Old Apr 15, 2003 | 04:01 PM
  #8  
2K2CamaroSS's Avatar
Thread Starter
TECH Apprentice
iTrader: (18)
 
Joined: May 2002
Posts: 323
Likes: 0
From: Aurora, CO
Default Re: Running Lean...how to fix this issue? (tuning newbie)

hmmm..okay I'm confused...

the MAFT will only lean out the car and not richen??
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Apr 16, 2003 | 10:58 AM
  #9  
2K2CamaroSS's Avatar
Thread Starter
TECH Apprentice
iTrader: (18)
 
Joined: May 2002
Posts: 323
Likes: 0
From: Aurora, CO
Default Re: Running Lean...how to fix this issue? (tuning newbie)

TTT

Will a MAFT help me or not?
Reply
Old Apr 16, 2003 | 11:21 AM
  #10  
MOBE's Avatar
TECH Addict
 
Joined: Feb 2002
Posts: 2,031
Likes: 0
From: Bailey, Co
Default Re: Running Lean...how to fix this issue? (tuning newbie)

A MAFT will allow for adjusting rich or lean conditions. I have been wrestling with this issue myself. My a/f was 14.8 on my last dyno, so I bouhgt a MAF Translator. Are you getting any KR? I am/was getting 4 degrees.

On a side note... Can anyone tell me what the symptoms of a burnt piston are? Just curious.

Thanks!
Reply
Old Apr 16, 2003 | 11:49 AM
  #11  
2K2CamaroSS's Avatar
Thread Starter
TECH Apprentice
iTrader: (18)
 
Joined: May 2002
Posts: 323
Likes: 0
From: Aurora, CO
Default Re: Running Lean...how to fix this issue? (tuning newbie)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by MOBE:
<strong> Are you getting any KR? I am/was getting 4 degrees.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I have no idea what KR is so I really couldn't tell ya <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
Reply
Old Apr 16, 2003 | 11:52 AM
  #12  
MOBE's Avatar
TECH Addict
 
Joined: Feb 2002
Posts: 2,031
Likes: 0
From: Bailey, Co
Default Re: Running Lean...how to fix this issue? (tuning newbie)

KR= Knock Retard (detonation/pinging causes KR, which pulls timing)

You should autotap it to see what kind of KR you are getting. With a 14.5 a/f, you are surely getting some.

<small>[ April 16, 2003, 11:54 AM: Message edited by: MOBE ]</small>
Reply
Old Apr 16, 2003 | 01:14 PM
  #13  
jimmyblue's Avatar
Moderator
iTrader: (11)
 
Joined: Mar 2002
Posts: 12,604
Likes: 7
From: East Central Florida
Default Re: Running Lean...how to fix this issue? (tuning newbie)

Why not put the stock MAF ends back on and
see what these do for you? That's likely to
put you back to the normal tune, at least.
Otherwise you would want to increase fuel by
8-10% to get a proper WOT mixture. This is
within the MAFT's range but you have a zero-
cost option available to you....
Reply
Old Apr 16, 2003 | 01:22 PM
  #14  
killer01ws6's Avatar
TECH Resident
 
Joined: Mar 2003
Posts: 770
Likes: 0
From: Troy Al
Default Re: Running Lean...how to fix this issue? (tuning newbie)

MOBE,
a miss, loss of pwr, high oil comsuption,
positve pressure in crank case, ie if you removed oil cap while running a lot of blow by or air.

usually would loose a valve before a forged piston though. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

2K2CamaroSS
What I ment is say if you car was normal and your referace was 0 you would have x amount adustment both ways, but in a bad + or - condition would limit adjustibity.
Sorry did not mean to confuse ya, I did not state that well. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
Reply
Old Apr 16, 2003 | 01:23 PM
  #15  
2K2CamaroSS's Avatar
Thread Starter
TECH Apprentice
iTrader: (18)
 
Joined: May 2002
Posts: 323
Likes: 0
From: Aurora, CO
Default Re: Running Lean...how to fix this issue? (tuning newbie)

well that's the thing...I ported and polished the Stock MAF ends so I don't have anything to revert to. I guess, I need to get a MAFT
Reply
Old Apr 16, 2003 | 01:26 PM
  #16  
2K2CamaroSS's Avatar
Thread Starter
TECH Apprentice
iTrader: (18)
 
Joined: May 2002
Posts: 323
Likes: 0
From: Aurora, CO
Default Re: Running Lean...how to fix this issue? (tuning newbie)

Thanx everyone for all the input. I guess it's time to buy a MAFT and get some tuning done
Reply
Old Apr 16, 2003 | 02:16 PM
  #17  
Vettepartz's Avatar
Launching!
 
Joined: Dec 2001
Posts: 250
Likes: 0
From: Albuquerque, New Mexico
Default Re: Running Lean...how to fix this issue? (tuning newbie)

Killer01WS6, when you say 12.8 is best for max torque and 13.2 best for max HP, I assume you mean on a dyno and using a wideband, not on the street. Should the curve stay near the 13.2 and dip to 12.8 at the max torque rpm, or stay at 12.8 and rise at the max HP rpm? In other words, what do you want the A/F to be at WOT (Cell 22) when you are not at the max HP/Torque rpm's?
Reply
Old Apr 16, 2003 | 02:20 PM
  #18  
MOBE's Avatar
TECH Addict
 
Joined: Feb 2002
Posts: 2,031
Likes: 0
From: Bailey, Co
Default Re: Running Lean...how to fix this issue? (tuning newbie)

Thanks killer! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Reply
Old Apr 16, 2003 | 04:07 PM
  #19  
BLK02WS6's Avatar
9 Second Club
iTrader: (2)
 
Joined: Jul 2002
Posts: 2,583
Likes: 1
From: on the dyno tuning in MD
Default Re: Running Lean...how to fix this issue? (tuning newbie)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 2K2CamaroSS:
<strong> well that's the thing...I ported and polished the Stock MAF ends so I don't have anything to revert to. I guess, I need to get a MAFT </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Buying a stock MAF would be cheaper than buying a MAFT! And get you out of a very dangerous situation!

The tiny gains that you get from that ported and polished MAF aren't going to be worth it when your motor is dead!
Reply
Old Apr 17, 2003 | 12:37 AM
  #20  
2K2CamaroSS's Avatar
Thread Starter
TECH Apprentice
iTrader: (18)
 
Joined: May 2002
Posts: 323
Likes: 0
From: Aurora, CO
Default Re: Running Lean...how to fix this issue? (tuning newbie)

hmm...now that you mention it, I do seem to hear some knocking under WOT excelleration.....Is this dangerous? at what extent will this cause damage?
Reply



All times are GMT -5. The time now is 11:56 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE