AFC Spring Kit

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I am not a total bonehead, but semi, when it comes to diesels. What is and does an AFC Spring kit do. If it is so cheap and have such rewards it would seem that everyone would have a kit on there truck. Thanks for the input.

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RamNProwler
Ed Council
Lake Stevens, Washington

1996 Black 2500 SLT CC, Atuo, 4. 10 LSD, Banks Power Pack, BD Torque Loc, Converter and Brake, Pyro , Boost and Trans Temp, Ultra Wheels, 28575R16 RVT Wild Country TIres, TekStyle Tonneau Cover, Lighted Sun Visor, Power Vision Mirrors, Spray in Diamond Liner, Diamond Plate Rail Caps,Amsoil throughout
LOVE THE POWER
Pull 27' Prowler TT all over Washington

 

[Archive]

When you change the fuel cam plate, and the AFC star wheel must be adjusted to limit smoke, it also limits the fuel rod movement. The spring kit uses a spring of a different length and ratio that alows better low end rsponse with less smoke and possibly more fuel at the upper end also.

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Paul A. Schmidt
95, 4X4, SLT 2500, 5 spd. , 4. 10, 270 hp. TST, AFC spring kit, Pacbrake, Walker muffler,
GearVendor O. D.
Eastern PA.

 

[Archive]

The Air Fuel Controller, is just what its name suggests . The AFC housing at the back end of p7100 injection pump and controls the rate at which fuel is delivered to the engine in relationship to the engine's boost level. The AFC housing uses a boost signal from the engine manifold to actuate a diaphragm in the AFC housing that is connected to a control rod that limits the rate at which fuel is deliver to the engine.

Short explanation. There are two adjustments to the AFC housing. There is a star wheel located under the 8 mil. allan head plug. The adjustment of the Star wheel increases or decreases the spring tension on the diaphragm allowing boost to fuel delivery ratio adjustments. Example: lower the spring tension on the AFC housing diaphragm and you will allow more fuel to be delivered to the engine at a lower boot level and visa versa. The kit provides two springs of lower compression ratings to allow faster fueling. The balancing act here is that it takes fuel to create boost. To much fuel over boost and you will get the dreaded black smoke out of the exhaust pipe. Not enough fuel and it will take for ever to create boost, thus making the truck fell like it has little or no power.

The second adjustment is what I call the "initial fuel setting" This is the initial amount of fuel you allow your engine to have before any boost is created. This adjustment can be accomplished in two ways. The first is by moving your AFC housing forward or rearward, not very easy and time consuming. The second and better method is using the adjustment set screw on the very back of the housing. This adjustment screw has an anti-tamper covered over it, about 1/2 inch long. Now this is where I say the TST instructions come in handy. They are very clear in how to adjust the AFC housing so that the diaphragm actuation achieves complete rack travel. Thus allowing a follower inside of the injection pump which meters the fuel delivery to "fully" follow the profile of the cam-plate.

One of the problems with higher horse power cam-plate swaps, is you don't always get complete fueling due the factory setting (and very stiff spring on the 215 hp engines) with the AFC housing. That is one reason for using the AFC spring Kit with a cam-plate instillation. I was very surprised at the noticeable increase in power after installing this on my truck when I was only running the 280 hp plate. I had the plate in for over a year before playing around with this kit. The return of knowing how to tune your engine is worth its weight in gold. I speak from many hours of tinkering, that I could have been saved if I had this information contained in the kit from day one.

I hope that I haven't confused the matter more. I'm sure that Ted Jannetty or Joseph Donnelly can correct me if I mislead anyone. DBR


[This message has been edited by DBR (edited 12-02-1999). ]

[This message has been edited by DBR (edited 12-02-1999). ]

 

[Archive]

Thank You for your extensive reply. I was thinking that the AFC Spring Kit was only for use with the TST Cam Plate. Since it is on the pump I do belive that it will work with the Ottomind fuel regulator that is put out by Banks also. I will have to look into this a little deeper but I think that I just found my next mod. Again Thank You.

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RamNProwler
Ed Council
Lake Stevens, Washington

1996 Black 2500 SLT CC, Atuo, 4. 10 LSD, Banks Power Pack, BD Torque Loc, Converter and Brake, Pyro , Boost and Trans Temp, Ultra Wheels, 28575R16 RVT Wild Country TIres, TekStyle Tonneau Cover, Lighted Sun Visor, Power Vision Mirrors, Spray in Diamond Liner, Diamond Plate Rail Caps,Amsoil throughout
LOVE THE POWER
Pull 27' Prowler TT all over Washington