Old guy Old Rabbit---both Happy.

[medwardl]

Forgot how much info Hagar has given us over the years. Just finished reading everything from the beginning. Finally ordered my Bentley book and if i can find one, hope to have a rabbit sometime in April then i get to put hillbilly tuning to good use.

[libbybapa]

Can we adjust "Mixture" ? yes but it is very complicated.

I've always found it easy to adjust the mixture constantly on the fly. Press the pedal harder to enrich the mixture and less hard to lean the mixture.

[Quantum-man]

Can we adjust "Mixture" ? yes but it is very complicated.

I've always found it easy to adjust the mixture constantly on the fly. Press the pedal harder to enrich the mixture and less hard to lean the mixture.

Yes but that's the hard bit [discipline wise]

"Run it rich, but drive her lean"

[hagar]

SAGA : "Mixture Explaned" (again).

"Leaning" it out will simply cause it to idle, "richening" it will cause acceleration/revving, or if excessively "rich" it will smoke black.

from the above statement we can deduce that if the Oldies are that confused then no wonder the Newbies are having troubles.. (I never get frustrated) so here we go again. :

You all know the "full-load" stop (screw) , the one with the SS stop collar welded on. EH ?. good . That one is very important. Think of one cylinder only . Since mixture is a ratio , what is variable ? THE FUEL. , the air inhaled is a constant at say 400 cc. , this is where us VW driver are way ahead of the gasser guys. Ignition will take place no matter how small or big gulp of fuel is injected.. Turn the full-load screw all the way in Clockwise. , then every stroke gets a maximum gulp ( amount is depending on plunger diameter and stroke.).

hagar.

PS : got to see the sawbone.

[medwardl]

I know you like using wax as much as possible, but what kind of difference would it make if i used the 120 av oil year round?

[hagar]

SAGA : medwardl 120 av oil is good for your Rabbit..

use just enough to bring viscosity up to make I P function. .Wax and heavy oil is for worn I P 's

hagar.

PS : please put your location on profile. (ask Vincent if you need help). Av Oil is good even for brand new pumps.

[mattbondy]

What about volumetric efficiency? Flow characteristics in intake will change pretty significantly with piston speed (RPM) (I would guestimate 20-30%) resulting in changes in mass of air. However, ignoring volumetric efficiency is probably pretty reasonable. Especially if you only consider a narrow vehicle speed range and one gear.

Is someone hinting at fuel injection timing? Is dynamic pump pressure related to injection timing?

[hagar]

SAGA : The mixture at idle is not for us to do anything about. . Fuel in sets the idle.

Where we run LEANED out is in the operating band. Lots of pedal little fuel EH BINGO that is how it is done.

hagar.[i][/i]

[libbybapa]

________________

[rabbit_man]

I keep having to chuckle a bit

The only reason "ECO mode" give better mileage is because it limits the fueling, with a little self control on the go pedal the same mileage can be had in non ECO mode......

With a diesel the stoichiometric ratio changes from idle to full power. So adjusting the "fuel screw" is the same as adjusting the go pedal, turning it out is just like putting a block of wood under the pedal and turning it in is like cutting a hole in the floor beneath the pedal.

It's not good to lead newbies astray by telling them that a leaner mixture will give better mileage, the main thing is to get the timing right and set the fuel screw so it won't smoke enabling it to burn what's injected.....

[hagar]

SAGA : libbybapa you are most welcome to say anything whatever on my post , and so is all members. WHY ? we all learn from discussions. , SO ? thank you.

hagar.

[wolf_walker]

This seems to be a recurrent point of debate, this governor/throttle bit.

I've read the Bosch book section on it more than a few times and am still digesting. One thing I know for sure from reading it is the control collar is not rigidly attached to your foot, it'd never work if it was. Saying foot throttle action is directly related to injected fuel quantity is in the least incorrect in *some* scenarios. I can site the sections of the Bosh Diesel Engine Management - Diesel distributor Fuel Injection Pumps if needed, but I suggest everyone interested in such find it online and enjoy. I don't have enough assimilated data right now to offer anything else. But I will.

[libbybapa]

________________

[wolf_walker]

Ok, somebody devise a test and figure this out. If the guy can post a video of a cutaway pump running to show governor action surely someone here can come up with something to settle this.

[libbybapa]

________________________