LT1-LT4 Modifications 1993-97 Gen II Small Block V8

New 355, is the Split BLM's or do I have a problem?

Thread Tools
 
Search this Thread
 
Old May 27, 2007 | 09:03 AM
  #1  
wrd1972's Avatar
Thread Starter
TECH Veteran
20 Year Member
Photogenic
Photoriffic
iTrader: (12)
 
Joined: Mar 2006
Posts: 4,668
Likes: 5
From: Central Kentucky
Default New 355, is the Split BLM's or do I have a problem?

The right side bank on my new engine is still showing 150-160 BLM's at idle and deceleration or basically anytime the throttle body is closed.
Here is a snapshot of my fuel cells:
Cell LBLM RBLM
2 135 148
3 130 138
6 127 127
7 121 118
10 128 121
11 126 123
15 128 128
16 135 160
17 130 150
18 130 145

The right side bank behaves normal. I intend to get the car dyno tuned but I want to make sure that the BLM is not a interfering problem. Currently I have Ion's tune installed.

I have checked for exhaust leaks, none apparent.
I have swapped the fuel injectors, left to right etc. no change.
I have looked for intake vaccum leaks, no apparent.
I swapped the O2's, no change.
I sprayed the intake openings with starter fluid, no change.
I checked the plugs, look normal with no blackness.
I checked the plug wires, look good.
The opti, plugs are all new.

Does anyone have any suggestion on how to resolve this, or is this the dreaded split BLM?
Thanks
Reply
Old May 27, 2007 | 03:03 PM
  #2  
buffman's Avatar
TECH Addict
iTrader: (9)
 
Joined: Nov 2004
Posts: 2,289
Likes: 0
From: Kzoo, MI
Default

what brand TB is on the car?
Reply
Old May 31, 2007 | 07:36 AM
  #3  
wrd1972's Avatar
Thread Starter
TECH Veteran
20 Year Member
Photogenic
Photoriffic
iTrader: (12)
 
Joined: Mar 2006
Posts: 4,668
Likes: 5
From: Central Kentucky
Default

Stocker bored to 58mm.
I used this same TB with my old stock motor and had no splits. At the time the BLM's were on the lower side at idle from what I remember.
Reply
Old May 31, 2007 | 10:38 AM
  #4  
azvforce's Avatar
On The Tree
iTrader: (-1)
 
Joined: Feb 2006
Posts: 159
Likes: 0
From: Phoenix AZ
Default

There is no way your stocker is bored to 58, biggest a stock TB can go is 52mm.
Reply
Old May 31, 2007 | 10:46 AM
  #5  
lt197formula's Avatar
TECH Fanatic
iTrader: (6)
 
Joined: Feb 2005
Posts: 1,070
Likes: 1
From: Buda, Texas
Default

Originally Posted by azvforce
There is no way your stocker is bored to 58, biggest a stock TB can go is 52mm.
That's what I thought too...
Reply
Old May 31, 2007 | 12:07 PM
  #6  
wrd1972's Avatar
Thread Starter
TECH Veteran
20 Year Member
Photogenic
Photoriffic
iTrader: (12)
 
Joined: Mar 2006
Posts: 4,668
Likes: 5
From: Central Kentucky
Default

Originally Posted by azvforce
There is no way your stocker is bored to 58, biggest a stock TB can go is 52mm.
Aw' crap, you guys are right.
I meant 52mm.
Reply
Old May 31, 2007 | 04:06 PM
  #7  
941LE's Avatar
Teching In
 
Joined: Aug 2005
Posts: 2
Likes: 0
Default

listen ,to have a slight difference between left and right banks is a normal accurance , is there a problem with the way the car runs ? any backfires,sluggishness??
you need to understand that long term memory for fuel maps are there to aid the pcm's abillity to adjust and control injector pulse width, if you can see short term memory that will give you a better understanding of how rich or lean each bank is running. Long term memory is used to have a base knowledge of were to start from. I do not think you have a problem by looking at those numbers
Reply
Old May 31, 2007 | 04:31 PM
  #8  
dhdenney's Avatar
TECH Veteran
iTrader: (53)
 
Joined: Feb 2004
Posts: 4,433
Likes: 0
From: Monticello, Kentucky
Default

Take it for all it's worth, my BLM's looked like that when I was trying to tune my VE tables (no MAF, SD). After I hooked MAF back up, fine.
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 May 31, 2007 | 07:35 PM
  #9  
wrd1972's Avatar
Thread Starter
TECH Veteran
20 Year Member
Photogenic
Photoriffic
iTrader: (12)
 
Joined: Mar 2006
Posts: 4,668
Likes: 5
From: Central Kentucky
Default

Car runs strong util the KR kicks in. That will need to be dealt with too.

There is no backfiring or sluggishness, it is very responsive. The problem is there only at cell 16 idle or any time the TB blades are closed. Once you raise the RPM's a bit from idle the high 160 BLM is gone. It will be dyno tuned in a few weeks, I hope.

I can monitor the short terms. What exactly am I looking for here?
Reply




All times are GMT -5. The time now is 01:36 PM.

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