Engine/Transmission (1994 - 1998) Plate Missing

[Troutman]

I was going to grind my own fuel plate today. But when i got under the hood and had everything apart i realized that my truck does not have a fuel plate in it. I also realized that my AFC was unhooked and both holes had been plugged. So i am working on getting a new plate. But my question is, i went ahead and plummed up the AFC so that it was again working. I expected a huge amount of smoke, having no plate, but it wasnt very different than with the AFC unhooked. Do you think that the AFC is still not operating or could i have something else wrong. The truck is a 94 auto. I just replaced the fuel filter and cheked my fuel pressure. As far as i know it still has the stock injectors. Any ideas would be great.

 

[CRohwedder]

my truck was also missing the fuel plate when i got it and the afc was not hooked up, truck ran fine and mine did throw quite a bit of smoke.

 

[Troutman]

I can throw some decent smoke... but i would think without a plate and with the afc hooked back up that it would be a stupid amount of fuel... or would it not change very much by hooking up the AFC???

 

[Joe G.]

If the AFC is not hooked up then boost will never move the AFC throttle stop back out of the way. If it is hooked up and working correctly then you will get a lot of fuel and smoke when boost increases to push the throttle stop out of the way. You need a plate or there will eventually be some pump damage that is expensive. Any plave, even a 0, will prevent that kind of damage. The AFC can be disabled so that the throttle stop is out of the way. The result of that is that the truck will smoke like a forest fire when you get on it.

 

[Forrest Nearing]

if the AFC is gutted, it won't be limiting fuel... was the AFC arm still in there?

 

[BTilson317]

i third that guys, i have a 96 2500 auto and my plate wasn't there, trust me i was confused as H*** but i went ahead and bought a fuel plate before i ever looked in the afc anyways, so i stuck a #6 tst plate in and i believe it does run more efficient and can't hurt the pump to have it now! good luck Troutman, get a plate in that thing i recomend a bought one over stock homemade ground one...

 

[Troutman]

The AFC arm is still in there... i dont think it is working properly though... i am looking around for a stock plate... because i would really like to make my own plate... it is something that i want to do... so if you know of anyone who would have a stock plate i could get that would be great... the diesel shop here in town quoted me 175 on a plate...



when i go to test the afc should i take it out of the truck and hook an air line to it... is that the proper way... thanks

 

[Joe G.]

That tests that the AFC works or not. However, even if it works for the air test it has to have boost to it. So take it off. Cover up the hole with something. Take a short test drive. If nothing changes then the AFC was not working or gutted. If the truck smokes a lot more when you get on it then the AFC was working. If the air test shows that it is ok and the drive test shows no difference then you are not getting boost pressure to the AFC.

 

[Troutman]

Thanks... im gonna do the drive test on monday with the AFC not on there... Thanks for all the help... ill let you know how it goes...

 

[JMiltier]

anybody got a diagram of the afc and pics of the pump opened up where the plate is and how to adjust the afc.

 

[Joe G.]

#ad




This shows the AFC. The mounting slots allow a course adjustment of the AFC. the fine adjustment is the star wheel.



Idle adjustment requires a box end 10mm wrench. There is a screw with a lock nut on the back of the pump. To the right in the picture above but it is not shown. Loose the lock nut with the wrench. Then take the pressure of the linkage off the adjustment screw by moveing the throttle with your left hand. Then turn the adjustment screw with your fingers until the idle is like you want it. Tighten the lock screw.

 

[ACrafts]

So if i understand this if you disable the AFC it will smoke like mad? If so how do you do this?? Oo.

Thanks

Adam

 

[CogginsP]

Adam -



Disabling the AFC is an intricate process and really people only do it if they are building a puller. When you disable the AFC the only thing governing the amount of fuel going into the engine is your right foot and you will more than likely overrev your engine and destroy everything. There are other ways to get smoke other than disabling (Removing) the AFC.

 

[Troutman]

What are governor springs for then...

 

[JMiltier]

how do u adjust the afc to get better air and lean it out some to burn a little more fuel?

 

[bmoeller]

The AFC "smoke screw" (star wheel) only plays a part in off boost conditions. Not running down the road. It is under the plug with the 8mm hex on the head.



More off boost fuel- turn towards the engine. Away for less.

 

[JMiltier]

so i want to turn it away cause it smokes at take off right?

 

[RWorth]

When you turn the star wheel towards the drivers fender you are putting a pre-load on the spring therefore it will take more boost to over come the pre-load of the spring to move the AFC arm out of the way so the governor spring can follow the profile of the fuel plate. The tighter spring will not allow as much fuel at low boost on take off. Turning the star wheel towards the engine has the reverse affect and therefore more fuel at low boost the AFC arm is out of the way of the governor arm sooner.



I went back to the stock spring when I installed the #10 plate with no pre load on the spring, basically the star wheel towards the engine until I could move the spring freely it takes 34psi of air for full travel of the AFC arm with TST medium spring I adjusted for about 20psi for full arm travel. I would like to find a spring that would allow for 30 psi full travel which allow more control of smoke and more room for placement of the AFC housing which would in turn give better smoke control.



Hopefully I explained this correctly.