Engine/Transmission (1994 - 1998) Im confused...star wheel vrs smoke screw

[97Turbo]

Truck was tuned by a shop I had putting in a ATS Stage 2 trans, fuel plate was ground to a #10 profile and moved forward , I have a 4" exhaust. EGT never goes over 1050 degrees at this point. I'm trying to get the best mpg with usable power. The tuner said he did the above mods but didn't touch the smoke screw or star wheel, should I do some minor adjustments on these? My confusion is exactly what each of these items do. I get only very, very minor smoke on full throttle. Truck is a 97 12 valve.

 

[LNaugle]

did you notice a difference afterwards?

 

[ewcmr2]

Smoke screw and star wheel are same thing. Basically it adjusts the amount of fuel available before boost is made.
More fuel sooner, with accompanying smoke, helps build boost faster. Smoke is unburnt fuel, if you have it you won't have the best MPG.

 

[97Turbo]

Smoke screw and star wheel are same thing. Basically it adjusts the amount of fuel available before boost is made.

More fuel sooner, with accompanying smoke, helps build boost faster. Smoke is unburnt fuel, if you have it you won't have the best MPG.

OK, I understand. Adjusted star wheel, got smoke, now I'm gonna tighten it up till the smoke goes away. Thankyou.

 

[97Turbo]

did you notice a difference afterwards?

Ahmmm, yes.



But I did a ATS Trans, fuel plate, 4" exhaust, etc, all at the same time. Just added the Pusher intake which woke it up from go to the top end and helped with slightly mpg. This is a former California truck so the intake was really restricted by the EGR area of the intake. Jury is out on mpg till I run a few tanks thru it. Overall I am happy with the mods, especially the ATS transmission package.

 

[LNaugle]

well a 10 plate isnt that much extra... with trans you could possibly go to a six... depending on turbo...

 

[97Turbo]

OK, so how about +40 sticks, a #6 fuel plate, 3K gov. spring, and a BD Super B or Aruora 3000 ?

 

[toms73novass]

Smoke screw and star wheel are same thing. Basically it adjusts the amount of fuel available before boost is made.
More fuel sooner, with accompanying smoke, helps build boost faster. Smoke is unburnt fuel, if you have it you won't have the best MPG.

I sort of have to dissagree with this.

The smoke screw is on the back of the AFC and it controls the amount of fuel before boost begins (the starting point for fuel) if is is in too far you will smoke as soon as you put your foot on the accelerator.

The star wheel pushes on the AFC spring and this controls the transient fueling ( basically from the setting of the smoke screw all the way to full throttle or when it hits the fuel plate). This controls the amount of power and smoke as the boost builds. If you get smoke after the initial application of throttle while accelerating, tightening up the star wheel (turning towards drivers fender) it will cause more tension on the AFC diaphragm and slow the amount of fuel being delivered.

 

[RVPILOT]

does shuddering at lo throttle around 41 mph have anything to with star wheel adj ? moved wheel fwd shudder decreased, smoked more turned wheel back less smoke shuddering less. never had this problem before with old pump and # 2 diesel dynamic plaate. stormy

 

[cerberusiam]

The smoke screw is on the back of the AFC and it controls the amount of fuel before boost begins (the starting point for fuel) if is is in too far you will smoke as soon as you put your foot on the accelerator.

The star wheel pushes on the AFC spring and this controls the transient fueling ( basically from the setting of the smoke screw all the way to full throttle or when it hits the fuel plate). This controls the amount of power and smoke as the boost builds. If you get smoke after the initial application of throttle while accelerating, tightening up the star wheel (turning towards drivers fender) it will cause more tension on the AFC diaphragm and slow the amount of fuel being delivered.

Thats closer than was posted earlier. Actually, the smoke screw is for idle tuning and controls fuel delivery when the throttle is closed. The star wheel controls no\low boost fueling when the throttle is advanced.