Cyl skewing in a V6

[MMGT1]

Found I have 1 cyl that is a little lean compared to the rest.(The old fashion way...looking at the plugs!!) I know I can skew the cyl to fix the problem but don't know what is a safe value to start with.
Would I add to the skew or take away from it? With AFR, when you subtract it gets richer, does the same apply here, or does increasing the value add fuel???

[MMGT1]

??thread has over twenty hits and no takers??

[Chris@HPTuners]

numbers greater than 1 add more fuel. It's a multiplier on the injector pulse width.

[usd2sing]

adding to this i have a question.

performing the cyl balance testing.
u come up with 1 cyl/inj off a little compared to all others.
for the topic lets say one is showing a 3-5% higher number.
example:
all are showing 93-95%,
then u have one that is showing 97-98%.

does this mean you need to add or subtract a % from that one cyl/inj.
1.03
or
.97?
to get the one skewing cyl/inj inline with the others.??

i havent had to mess with it too much yet, but the question does arise pretty often.
thanks.

[MMGT1]

Ok thanks Chris. Is this one that I'd move it up .1 at a time or would you use .05 to start with and go in incriments of .05 until it looks good?

[Chris@HPTuners]

the value is a multiplier, so 1.05 is 5% more fuel to that cylinder, 1.10 is 10% more fuel etc.

[MMGT1]

Gotcha.....thanks Chris. See why I used this( ) in the title. Knew it would be a lot simplier than I thought it was.



I'll do the 2% thing and see where that leaves me. Add a couple at a time till the plug looks good.

[Dr.Phat]

What are you looking for in your plugs?

Can you possibly post pictures of what a good and a rich and lean plug looks like?

[MMGT1]

I just tried to get a shot for you and they look almost the same in the picks, I think because of the flash?? But this is easy enough. When I pulled my plugs on Sunday I found one was, how shal I say, "whiter" than the rest. Five of my plugs looked very normal (slightly brown with no signs of over spark or shorting out. Electrode is same colour as the ground strap) Looking at the porcelin insulator will tell the tale. Really it's a simple as dark and carboned is too rich. Slightly brown is "good", and a wite"ish" plug is too lean. Now this will require a bit of fooling with my fueling again with the wideband because I'm sure this will throw off the tune a bit, but shouldn't be that bad. Gives me an excuse to toss the wideband in again

Got one to work: http://www.putfile.com/pic.php?img=5157037

The one in the middle is the lean one.

[Dr.Phat]

Wow, that pic turned out pretty good.

Now here's a good question, what if all the plugs looked like the center one?

I usually only pull my plugs after I have a track day, and run a bottle of Torco through the gas tank. Torco turns the plugs orange, and all of them looked the same, so I'm not too sure if I'm going too lean or not.

My narrowband O2's are around 930 or so, going from 910-940 usually at WOT.

[MMGT1]

Narrow to narrow can be really different. But your range does sound right. Narrow is still a guess though. If all plugs look the same you have even fueling across the cycls. Keeping an eye on your plugs is always good practice. Don't trust the computer to do everything!!