lean vs rich cylinders

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Jun 20, 2007 | 10:32 AM

billiardcue

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Racer

Joined: Feb 2004

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From: Roanoke VA

lean vs rich cylinders

Which cylinders on an LSx typically run the leanest, which run the richest?
Why don't both banks run the same air fuel ratio?

Jun 20, 2007 | 10:37 AM

dougbfresh

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???? Why do you think some run leaner/richer than others?

Jun 20, 2007 | 11:02 AM

AU N EGL

Team Owner

Joined: Sep 2003

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From: Raleigh / Rolesville NC

#7 runs leaner. #8 has the least oiling and cooling around the cyclinder.

a good tuner can tune or turn up the A/F ratio of #7 without effecting the others.

#7 and 8 are the two problem cyclinders in the LS1, LS6 motors.

Jun 20, 2007 | 11:13 AM

dougbfresh

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How would you know for sure without sampling exhaust gas seperatly? Maybe EGT on each cylinder?

Jun 20, 2007 | 11:15 AM

Smoove

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Quote:

Originally Posted by dougbfresh

How would you know for sure without sampling exhaust gas seperatly? Maybe EGT on each cylinder?

Yes, EGT each cylinder. Or you can just base the tune off of #7. Like someone above already said(i think).

Jun 20, 2007 | 11:23 AM

billiardcue

Thread Starter

Racer

Joined: Feb 2004

Posts: 455

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From: Roanoke VA

Most engines typically have cylinders that run leaner or richer than the rest due to the intake manifold design, throttle body position, etc.
I would assume that cylinders 7 & 8 run the richest as they are furthest from the throttle body.
Bought new injectors and they are flow rated so I figure I'll match them to the motor's inherent properties.
I know that the left bank runs leaner as I have two wideband O2 sensors.

Jun 20, 2007 | 11:36 AM

billiardcue

Thread Starter

Racer

Joined: Feb 2004

Posts: 455

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From: Roanoke VA

Quote:

Originally Posted by AU N EGL

a good tuner can tune or turn up the A/F ratio of #7 without effecting the others

How do you do this?

I use EFILive.

Jun 20, 2007 | 11:43 AM

dougbfresh

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Can you adjust injector pulse width individually?

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Jun 20, 2007 | 11:59 AM

vettenuts

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From: At the beach in little Rhody

I had my injectors cleaned and flowed. I put the two that flowed the most in 7 & 8 as a precaution since I knew the numbers.

Jun 20, 2007 | 12:43 PM

#10

FRCTony

Drifting

Joined: Mar 2005

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From: Northern VA

Quote:

Originally Posted by dougbfresh

Can you adjust injector pulse width individually?

Not with the stock PCM.

Jun 20, 2007 | 02:27 PM

#11

dougbfresh

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Quote:

Originally Posted by FRCTony

Not with the stock PCM.

SO, that would mean adjusting a single cylinders A/F ratio would not be possible with a stock PCM?? I would think it's an all or nothing proposition with the stock computer.

Jun 20, 2007 | 02:35 PM

#12

blkvett01

Racer

Joined: Apr 2004

Posts: 391

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From: Garland Texas

I might be wrong but in HP tuner you can adjust the table by left bank and right bank. In the table map i saw adjustment for that but not sure about each injector i think it is left and right, just like the o2 sensor read left anf right bank.

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