PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Lean bank due to lifter issue?

Thread Tools
 
Search this Thread
 
Old May 3, 2009 | 05:56 PM
  #1  
LS1-450's Avatar
Thread Starter
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default Lean bank due to lifter issue?

Has anyone experienced this. Been trouble shooting unburnt fuel firing in the exhaust & noted that bank 2 is adding alot of fuel. While turning the engine over w/ the starter, everything looked OK w/rocker movement.

Have checked everything except removing the head to replace lifters. There is a lifter tick. Rockers are OK, pushrods OK, spring heights OK, valves appear to be OK...leak down test is next prior to removing head, but am not expecting an issue (it likely wouldn't be causing the lean condition if there were a pressure problem). Intake vacuum is not connected to either valve cover or the valley nipple.

It must be the lifters or a lifter. Please comment, thanks.
Reply
Old May 4, 2009 | 02:06 PM
  #2  
NoGo's Avatar
TECH Addict
20 Year Member
Photogenic
Photoriffic
iTrader: (2)
 
Joined: Jan 2002
Posts: 2,814
Likes: 110
From: Mass
Default

If there is a serious compression issue then you may have a dead (or near dead) hole....which in a round-about way will crank alot of fuel into your exhaust.

Is there an LTerm/STerm split between the banks? Or one bank indicating much leaner then the other?

If there is a serious tick that coincided with fuel getting into the exhaust, then I would put my money on a compression or leak down test.
Reply
Old May 4, 2009 | 02:07 PM
  #3  
NoGo's Avatar
TECH Addict
20 Year Member
Photogenic
Photoriffic
iTrader: (2)
 
Joined: Jan 2002
Posts: 2,814
Likes: 110
From: Mass
Default

FWIW, all of the valvetrain problems that I have ever encountered that screw up the fueling of the motor cause intake popping as well.
Reply
Old May 4, 2009 | 04:35 PM
  #4  
LS1-450's Avatar
Thread Starter
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default

It's fixed; it was an injector wire issue.

Thanks for the replies.
Reply
Old May 5, 2009 | 01:15 AM
  #5  
99RTA's Avatar
Banned
iTrader: (-1)
 
Joined: Apr 2009
Posts: 250
Likes: 1
Default

I'd like to know what the issue was. TY
Reply
Old May 5, 2009 | 06:13 AM
  #6  
LS1-450's Avatar
Thread Starter
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default

Originally Posted by 99RTA
I'd like to know what the issue was. TY

A wire inside the injector weather seal had become disconnected. Couldn't see it because it was inside the weather seal. When I went to re-install the injector clips after checking injectors w/ a 12v power source, saw that the wire had come out of the seal enough to notice that it was no longer attatched to its' pin conector. Checked the spark plug & sure enough, it had signs of heat (no fuel). So, the non-fueling injector had created a lean cylinder of which caused the fuel trims to add gobs of fuel in that bank. The problem was corrected, once the wire was re-attatched & the injector began sending fuel again.
Reply
Old May 5, 2009 | 06:59 AM
  #7  
99RTA's Avatar
Banned
iTrader: (-1)
 
Joined: Apr 2009
Posts: 250
Likes: 1
Default

It didn't show a miss fire in that cylinder?
Reply
Old May 5, 2009 | 08:22 AM
  #8  
LS1-450's Avatar
Thread Starter
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default

Originally Posted by 99RTA
It didn't show a miss fire in that cylinder?
No missfire detected.
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 5, 2009 | 08:40 AM
  #9  
LS1-450's Avatar
Thread Starter
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default

Just checked the missfire diagnostics. Prior to buying tuning software, the previous tuner told me that he dampened the missfire detection due to the cam. Actually, he completely dissabled missfire detection by entering 32... into each cell. This explains why there was no missfire detected. I am now searching the EFILve tune repository for a tune w/ dampened, but not dissabled missfire file. Live & learn....I guess
Reply
Old May 5, 2009 | 11:09 AM
  #10  
99RTA's Avatar
Banned
iTrader: (-1)
 
Joined: Apr 2009
Posts: 250
Likes: 1
Default

Yeah i wondered about that....I know even gm's stock tuning won't show a missfire with a MIL unless its a dead miss and often. I just found that out, I had a plug that was partially fouled and was missfiring but the computer just ignored it. Finally got so bad i just started pulling plugs.
Reply
Old May 5, 2009 | 02:40 PM
  #11  
LS1-450's Avatar
Thread Starter
TECH Junkie
iTrader: (33)
 
Joined: Aug 2005
Posts: 3,783
Likes: 9
Default

Thought I had it fixed & the rich fueling remained. Ran a log side by side w/ the tune file & found that the 7.5.5 upgrade software is doubling the ECT temp in the ECT vs MAP OL fueling table. So, @ 65*C it registers 130*C. As a result the fuel trims start throwing gobs of fuel @ it & even more once it thinks it has reached engine protection temperature. Basically, there were 2 issues, the injector wire & the software.

The F9 table & the F10 dashboard both show 65*C when the ECT vs MAP is using 130*C. Either I've missed something or there is a software issue w/ the 7.5.5 upgrade. This was the additional cause of the bang in the exhaust. Problem happened again today which led to the side by side comparision.

So, now I've ruined @ least (1) 02 sensor & who knows how many more plugs.
Reply




All times are GMT -5. The time now is 02:01 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