[cummins916]

this isnt my first time turning up a cummins 12 valve but i did one last night for a buddy this is what i experienced i took the smoke box off grinded the cam plate down and turned the afc up And got NO SMOKE can some one tell me my problem ive done a bunch that way...

 

[Graphic Man]

moved the thread so our 12V members can help you out :thumbsup

 

[SmokinDiesel]

I have been dealing with 12 valves for quite a while ... and never heard of anyone call anything a "smoke box" ... :lol3:

How exactly did you grind the plate? ... Where did you set the plate at? ...
How did you tune the AFC? ...

 

[Racer9]

I assume the "smoke box" is your name for the AFC housing. Take it back off (cover the hole with a rag) and run the truck, to see if it smokes. If it does your AFC needs work. If it doesn't check the fuel supply lines, pre-filter, etc.

 

[cummins916]

this is a 12 valve

the smokebox is like a converter its on the exhaust for emissions:lol3: and the afc housing covers the cam plate what i done was grind it down to meet a #4 plate and the spring on the governor i turned it all the out!!!!! i have done this a few times and all the other times it made smoke but this is acheap free mod my truck has been fire ringed head studded #0 cam plate fass fuel 150 5in straight pipe turbo back hx50 turbo doul pin fixed and put more timing in it

 

[cummins916]

i ajusted the plate all the way towards the front of the truck and what do u mean by tuning the afc its a spring with a starwheel i loosened it all the out

 

[Racer9]

The AFC's function is to control pre-boost fueling (smoke). There is a pressure line to it from somewhere in the intake circuit (after the turbo) that allows it to move the AFC arm out of the way so that full fuel can be achieved, once boost has occured. If there is a malfunction in the system, the arm won't move enough to allow full fuel. You could have a blown diaphram, broken boost line, or other problem. Loosening the starwheel adjusts the amount of boost pressure needed to move the AFC arm, but if you have another problem the arm still won't move.
Thats why you should take it right off and run the truck. If you get smoke, you know the problem is in the AFC. If you don't, then the problem is elsewhere. You'll know the first time you hit the pedal.
Couple other thing's, slide the AFC full forward, and check to be sure that the shutdown arm is fully lifting, and not binding.

 

[cummins916]

that totally made sence ill try that in the morning and let you know so if i have the afc off i can start the truck if it smokes then what could be te problem the turbo is a whole lot louder then normal and its stock the silencer ring still there also.... thanks that a big help also on my truck it leaks some fuel at the returns i replaced the o-rings and there right back to leaking

 

[Dual K20s]

Alright, first of all learn to use a little punctuation. You'll get much better advise if we can understand what you said the first time we read it.

Second, yes gut the AFC for a run and try it. I think its easiest to remove the arm and put the housing back on as a cover. Just pull the 10mm bolt off the front of the AFC and slide the rod out, and the arm will fall out. Put the rod back in and bolt the hosing back down.

Also I suspect the fuel filter is clogged.

 

[Dual K20s]

And to clarify for all, you can't "turn the AFC up" ................. you adjust it

And you can do more to it than slide the housing around and turn the starwheel :w:

 

[95 SLT]

No Smoke ??

I turned my starwheel towards engine about 15 clicks, #10plate, boost elbow and housing fulll forward.

Man does she smoke..........especially in the bottom end. When I floor it at 1,000 rpm you will disapear in the rear view.

She honks.

You probably turned it out to far is my guess and lost something.
Also you must get fuel from a healthy lift pump and a clean filter.

Oh, and what about the fuel pressure release valve ?? very important.
I did 2 trucks where those were absolutely shot.

There's more to it than just the torque plate.

 

[cummins916]

well thanks everyone i actually figured it out first off it was the afc.... also the boost line was leaky so i elimanated that and still no smoke so i kept messing with the afc housing and i checked the diapram it was good.. well i took it all the way off and the rod was alittle tweaked so i took mine off my truck and started his and it ROLLED COAL so we replaced that and HE'S HAPPY WITH IT RUNS STRONG FOR A STOCK TRUCK!!!!! THANKS GUYS!!!!!!
NOW ON MY TRUCK I WANNA PUT SOME TIMING IN THE MOTOR GIVE ME SOME GOOD IDEAS I KNOW STOCK ITS RETARDED (NOT A CLUE HOW MUCH EXACTLY)BUT I WANNA ADVANCE IT ALITTLE JUST HOW MUCH WILL STILL BE SAFE......