Playing with my LM-1... a few Q's about AFR's+BAE

[air-cool-me]

Its K -basic btw

alright... so i plug it in and get a nice whoping 12.6 at idle...
Seems a bit fat for Idle... but i dont know much
on the highway im pushing 12.0...
WOT im looking at 12 with dips into the 11's
Since i get piss poor gas MPG i dialed idle back to 14.5

Round 2:

Idle 14.5

freeway still at 12.5

WOT at 11.8-12.5



so my question is... am i suposed to be pusing 12's on the freeway? is there any way to lean that out without messing up the rest?

i just cringe at the 1600mile trip in a few months at 12.5...or is that normal?


im about to install a BAE Turbo Kit... should i just keep it like this? is this rich enough?.

[KobaltBlau]

12s on the freeway are not ideal but since you have K-basic without closed loop control (lambda) it may be normal (I don't know, but for a closed loop car that would be bad).

if you put a BAE kit on everything is going to change.

[air-cool-me]

yea... maybe i should just be happy... at least its not lean!

[beepbeep]

12.8 is quite optimal for power @ WOT. Richer than that and you are just spewing out unburnt hydrocarbons and generating less power. For cruise, something around 14.7 wold be optimal. People believe that eninge will instantly self-destruct as soon as you touch other side of 14.7 but that's far from truth. Cars can and will run at stochimometric (and even slightly lean) at cruise. It's just lean mixtures at WOT accelleration that should be avoided, due to soaring temperatures and air-cooled engines inherently bad thermal design.

What is "K- basic"? K-Jetronic? K-Jetronic is made to provide optimal mixture when driving, partly trough different cone-slopes in the air-flapper.

If you are having constant problems with mixture being too rich, it might indicate problem with your control-pressure being too low (usually controlled by WUR), which would increase amount of fuel injected troughout the range.

Idle CO can be adjusted by a screw, but AFR can be adjusted only by manipulating controll pressure.

Turbocharger won't make this better in any way. K-Jetronic doesn't know what is inhaling the air...it just squirts gasoline proportional to air, and that proportinality is slightly out of whack in your case.

[KobaltBlau]

K-basic is K-jetronic before they implemented the lambda control system; it is K-jetronic without a closed loop mode. You might just call it K-jetronic but K-basic is used to explicitly differentiate it from K-jetronic with lambda.

[mikemdd]

" Idle CO can be adjusted by a screw, but AFR can be adjusted only by manipulating controll pressure."

Please explain....isn't CO and AFR related? I assume that any changes made by adjusting CO at idle are present throughout the range.

Thanks

[beepbeep]

My understanding is that idle CO adjustment has little influence at higher flow levels.

[sammyg2]

Yep, because you have an idle mixture that is leaner than at steady cruise you have one of two things going on here:

You may have a small vacuum leak that affects the idle mixture but isn't big enough to make much difference at higher air flows,
or you have a control pressure problem.

You really need to put a pressure gauge on the control pressure to diagnose your over-rich mixture and make sure you don't have any vacuum leaks. Does your idle drop when you pull the oil tank cap off?

You should have around 14-14.7 at idle, at least that lean at part-throttle steady cruise, and between 12 and 13 at full throttle.

Thast same rule of thumb applies with the turbocharger, the only time you want the fuel mixture to be different when adding a turbocharger is at full throttle full load, then you want to make sure it is a little more rich, even then no richer than 12 to one.

Your gas mileage must really suck right now.

[air-cool-me]

Your gas mileage must really suck right now.

you have no idea...


yea the RPM drops when the oil tank cap is off. is it still possable that there is a small leak?

just today i noticed that it dosent want to Idle even though its pegged on 14.5-1

if i richen it up a bit.. to lets say high 13's it idles great...

i will get her all hooked up to a pressure gauge and update in a few days...

[beepbeep]

Make sure that your exhaust doesn't leak too...it might offset your WBO2 readings