too much smoke
#1
#7
That smoke-screw (that accessed from outside the IP) only sets the no boost position of the fuel-pin. Backing it out, reduces the starting point or absolute minimum fueling as controlled by the AFC system.
If the truck still smokes excessively while the engine is winding up and/or under a mild~moderate load, then you need to adjust the Star-Wheel. As you know, the AFC controls the fuel input based on boost provided by the turbo. The more boost (air) it's sees, the more fuel it allows. Too much fuel with too little boost can make a smoky-hot engine that's not as peppy as it can be.
There's a spring under the fuel-pin's diaphragm that counters the boost pressure. As the boost pressure rises, it counters the spring and moves the fuel-pin, giving more fuel. The Star-Wheel allows you to adjust the spring pressure. The more spring pressure, the more boost has to be available to move the fuel-pin. Less spring pressure allows less boost pressure to move the fuel-pin. Turning the Star-Wheel one way or the other will allow you to best match the given amount of fuel to the currently existing amount of boost.
Too much fuel with not enough air (boost), runs much too rich and acts to quench the flame. It makes the fuel burn too slow thus, smoke (unburned fuel) out the exhaust.
Too little fuel with a lot of air (boost) makes no smoke but the engine isn't making the power it could at that air-flow level (boost).
Too fix it correctly so that the AFC is doing what it should, you'll have to disassemble the AFC cover, adjust the Star-Wheel, then put it back together. Now drive the truck around making not how much smoke is blowing out the exhaust.
Too much smoke? Go back in the AFC and tighten the spring (turn the star-wheel so it rises and increases the spring pressure). Then drive the truck again and note the smoke.
Too little smoke and/or the engine seems weak?. Go back in the AFC and loosen the spring (turn the star-wheel so it lowers and reduces the spring pressure). Then drive the truck and note the smoke.
You may have to adjust the star-wheel . . 3, 4, maybe 7 times or more to get comfortable with the throttle response while limiting the part-throttle smoke.
> Be sure you understand that we're talking about the smoke the engine makes as you leave a stop-sign and drive as one should on an open public road. Part-throttle, low to mid boost type stuff. That's the smoke we're adjusting. Not the wide-open throttle stuff.
Make sense?
If the truck still smokes excessively while the engine is winding up and/or under a mild~moderate load, then you need to adjust the Star-Wheel. As you know, the AFC controls the fuel input based on boost provided by the turbo. The more boost (air) it's sees, the more fuel it allows. Too much fuel with too little boost can make a smoky-hot engine that's not as peppy as it can be.
There's a spring under the fuel-pin's diaphragm that counters the boost pressure. As the boost pressure rises, it counters the spring and moves the fuel-pin, giving more fuel. The Star-Wheel allows you to adjust the spring pressure. The more spring pressure, the more boost has to be available to move the fuel-pin. Less spring pressure allows less boost pressure to move the fuel-pin. Turning the Star-Wheel one way or the other will allow you to best match the given amount of fuel to the currently existing amount of boost.
Too much fuel with not enough air (boost), runs much too rich and acts to quench the flame. It makes the fuel burn too slow thus, smoke (unburned fuel) out the exhaust.
Too little fuel with a lot of air (boost) makes no smoke but the engine isn't making the power it could at that air-flow level (boost).
Too fix it correctly so that the AFC is doing what it should, you'll have to disassemble the AFC cover, adjust the Star-Wheel, then put it back together. Now drive the truck around making not how much smoke is blowing out the exhaust.
Too much smoke? Go back in the AFC and tighten the spring (turn the star-wheel so it rises and increases the spring pressure). Then drive the truck again and note the smoke.
Too little smoke and/or the engine seems weak?. Go back in the AFC and loosen the spring (turn the star-wheel so it lowers and reduces the spring pressure). Then drive the truck and note the smoke.
You may have to adjust the star-wheel . . 3, 4, maybe 7 times or more to get comfortable with the throttle response while limiting the part-throttle smoke.
> Be sure you understand that we're talking about the smoke the engine makes as you leave a stop-sign and drive as one should on an open public road. Part-throttle, low to mid boost type stuff. That's the smoke we're adjusting. Not the wide-open throttle stuff.
Make sense?
Last edited by BC847; 09-10-2011 at 07:17 PM.
Thread
Thread Starter
Forum
Replies
Last Post
mattshow123
12 Valve 2nd Gen Dodge Cummins 94-98
14
03-12-2018 01:41 PM
gagemotors
24 Valve 2nd Gen Dodge Cummins 98.5-02
1
06-09-2015 04:24 AM