D24TIC Air Fuel Control (AFC) Valve

[DLM48]

does anyone have info on how to set the AFC to the std setting i 'think' mine was 'tweaked' for MAX POWER :-)

thanks in anticipation

[69dieselfreak]

give us a pic to see what we are looking at

[DLM48]

Originally Posted by 69dieselfreak

give us a pic to see what we are looking at

no pics today

read here

http://www.vwdiesel.net/phpBB/viewto...&highlight=afc



What this didn't cover as I had already covered it during this persons build up are the upfront costs. **These things must be in place b4 any thing you start to mod.

1. ***Exhaust from turbo back at lest 2.25" mandrel bent 2.5" is ideal, 3" is doable but takes alot more fabing.

2. Gauges. egt gauge, boost gauge, are the minimum, if you are going to do the govener mod then add a tach to that.

3. Intercooler, a poor intercooler is worse then none at all so choose wisely ( I am not the authority on intercoolers so someone else will have to jump in here.

4.**optional but highly recomended**1.9L metal HG, and arp, or raceware or, jan b's cheap head bolts or studs.

****WRITE DOWN EVERY ADJUSTMENT YOU MAKE, SO THAT IT IS EASY TO RETURN TO STOCK SETTINGS FOR EMISSIONS OR WHATEVER****

Ok lets start with the max fuel screw as even with out extra boost these motors can still definatly use extra fuel, so for this mod just break off the coller (either remove completly form pump and then remove or find the seam and pry it off with a well pointed flat blade screw driver. Then start turning it in until ether you chicken out, or your idle goes above 1200 or so with the idle screw turned right out (with the exhuast and intercooler setup you have if you run enough boost to burn this fuel (ie around 15-20psi) you will run lower egt # then a stock vwtd.

From here lets move to the the top of the pump under which is located the starwheel the diaphram and the anroid pin.

On the very top is a cap with a 13mm lock nut around a torx screw (i think its a T-25) this is referd to as the smoke screw as it adjusts low rpm / load fueling by turing it clock wise you increse the fuel and normally the smoke and visa versa, a good place to start is about two turns in.

Now lets remove the four screws holding the cap down pull off the cap and you will see a large rubber diaphram **(there should be a puch mark on the metal center take note of the direction it is pointed), with some wiggling and sometimes the added help of a flat balde screwdriver prying on the metal center this should come out with a spring and a nylon washer, at the bottom is the ecentric cone that the anroid pin rides on, if you look around the cone you will see exactly where the pin rides (ware mark) now take the nylon washer and compare the its thickness to the the amont of pin travel to the top of the cone, remove that much from the washer so the pin now can travel to a hair shy of the top of the cone. Incase you havn't realized the amount that pin travels is the amount of fuel avalible under boost so now when we replace the cone and the diaphram we will replace it so that the pin is now riding on the steepest section, BUT before we replace it lets look down into the hole where the starwheel resides. The star wheel adjustment sets the spring tension on the fuel load delivery rate diaphragm. If your star wheel (under the AFC spring) is set too high, the delivery rate pin won't move downward as it should with increasing boost levels. Turning the star wheel up (counterclockwise) increases the spring pressure, and slows the delivery rate. I'd suggest turning the star wheel down (clockwise) in 1/4 turn increments until you smoke, then back off (counterclockwise) till smoke is gone to your satisfaction, or smoke on under power, a black haze, not a black soot cloud. The retaining lock spring doesn't have to be removed, the star wheel will rotate with a small screwdriver gently placed and pried between the wheel and it. Note the location of the wheel, mark it, and count any turns for reference. Remember: Star wheel down=less spring resistance=increased fuel delivery rate.

Ok so far all of the above mods have been free, just basic tuning built into the motor. These next mods may or may not be free depending on your skill and the tools you have.