Okay I am having a little bit of problems trying to adjust the star wheel, maybe I am not doing it right. I am adjusting the screw which takes a Torex bit on the top of the AFC, which is on top of the fuel pump right? I am supposed to just loosen it up a bit right? Or am I doing this completly wrong? Either way I can't get the **** screw loose. So am I doing this right?


Travis

 

You have to take the Allen head plug out of the AFC housing. Inside of the hole were the plug was, will be a star wheel. Turn the wheel towards the motor which will loosen the spring which gives more pre-boost fuel.

 

It should be a 8mm, not a Torx. At least my 97 is. Also, the first time I took out the plug it was WWAAAYYY tight!! I was afraid it would break something, but it did not and I was just careful not to tighten it as much when I put it back together.

George

 

Ahhh Okay this makes sense now. Thanks

 

U can also use a 5/16th as well..

and the rest of the stuff has already been said..

Rick

 

Yeah just use an 8mm allen key and give it hell. It took some force when i did it the first time. After you get the plug out you'll see a spring and the starwheel. I used a flathead to turn the wheel a few times....

Hope you figure it out!

 

There's a washer under the plug , watch you don't lose it.

 

so how many turns is needed to increase pre-boost fuel? clockwise to increase or decrease?

how bad does this reduce mileage? if any.... what should be the result when done properly?

 

On an otherwise stock truck I would only go a few turns, it is not a precise setting, everyone has a different preference. Most loosen it to the point where you have good off the line acceleration, without excessive smoke. But what I call excessive the next guy might think is not enough.

If you set it not to cause billowing clouds it won't hurt milage, and seems to actually help a bit because it it what spools the turbo. (Try tightening the snot out of it, it gets laggy, and you mash the pedal a lot to get some acceleration.)

I am gonna have a fairly easy day, call my cell if you get a minute...

 

Alright so I am kind of upset. I pulled off the blug and saw that the screw was almost to the very front of the housing so I can't turn it anymore. The only time this thing smokes is on start-up. Is there something else I need to do to make it smoke? I am going to change the fuel filter tonight in case that might be the problem....Any ideas?

 

I think you started out with the "smoke screw". It is on the back of the AFC housing and is protected by a domed cover. Two screws to get the cover off, one of them is a tamper-proof screw. Once in there is a locknut on a stud with a torx head on it. Loosen the locknut and you can turn the stud. IIRC turn in for more fuel, out for less. The stud rests on the diaphragm for the AFC. Then you can mess with the starwheel as further adjustment.

You can also gut the AFC. That will allow full fueling all the time without any restriction. You simply remove the bolt (10mm head?) on the front of the afc housing and pry out the shaft using a flat screwdriver. It has an oring to seal it up. Once you get the shaft out you can take the arm out of the AFC box alltogether. Then you put the shaft back in and bolt it tight again. It will smoke that way, but I have no idea what else it does (egt, etc.) You have to kind of roll into the accelerator to keep it from smoking if you do that and I don't know if you would want to do it if you tow a lot. Maybe some of the more experienced can add to this.

 

just put in a # 10 fuel plate and then use the star wheel for final adjustment. if you had a 24 valver, it would cost you a lot more on electronics then your p pump upgrades cost, and you'll be very happy

 

I have no scientific backing on this, but it seems to me from the many posts Ive read and my own experience, that trucks seem to respond differently to the afc setting.
When I lived at an altitude of 6000 ft, the afc screw didnt seem to make any difference other than the amount of smoke.
Now that I live near sea level, the afc setting really doesnt seem to make that much difference at all. (Including the amount of smoke).

 

It says on the TST page that i would have too high EGT and my clutch couldnt handle the #10, so how about the #12?

 

off the subject how did u get a 13spd om this truck