I orginally posted a fuel issue thread in the gen3 external section. How do I move it to here, since this seems to be the correct section. Need some help.

 

I need some help on moving a thread.

 

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" Copy - Paste ? "

 

Well this is in here now so what's the problem..

 

OK, many times when the post is in the wrong area, the moderator moves. In lieu of that, the following is the problem. I have an LS1 that runs smooth and strong. It uses alot of oil, but it doesn't puff smoke unless it is reved up over and over. The plugs look normal, meaning they are tan with no oil or carbon build up. There are no oil leaks.

At WOT, it puffs black smoke, and the oil turns black within 300 miles. I had the tuner check it out because I thought the tune was too rich. He said it was ok, and that it was probably the second ring. If the rings were 20 yrs old and stuck I would agree but the motor was re ringed 2 yrs ago. All cylinders are with 10-15 lbs of each other. I've had three injected motors over the years and too many to other non injected motors to count.This one has me stumped. Any thoughts or guidance would be appreciated.

 

When you say 10-15lbs of each other, I'm guessing you are referring to a compression test. It wouldn't hurt to do a leak down test also.

What type of PCV system are you running?

Years ago, when I build a SBC 406 and I installed the second ring upside down, that thing smoked like a freight train at WOT.

 

Yes CR. The motor has the LS6 lifter cover PCV and vents through there. When I remove the oil filler cap and place a sheet of paper over it doesn't move while the motor is running. There is a small leak about nickel to quarter size in the morning. I jacked up the car and ran the motor for 20 minutes looking for leaks, but didn't see one. It only appears after driving the car and sitting all night.

The motor does not smoke, but it uses oil. The leak is too minor to be the culprit. The car runs great.

 

Could be burning oil, I'd want to know what the AFR is through the RPM range.

 

I agree, The motor puffs black smoke at WOT and the tuner said it was in spec. I guess I'll try a leak down check but need some advice for these motors. The last leak down test I did was on a 400 SBC.

So, I thought I would do this:
1) remove all the plugs
2) take off the intake to strip the motor down to the lLS6 rocker cover
3) pressurerize each cylinder and note if it leaks through the intake or exhaust valves or bleeds out through the lifter cover vacuum tube or rocker vents.
4) do the above first, then add oil to each cylinder and repeat.

Any other thoughts would be appreciated. Thanks.