You will be able to make the same or more power with the power screw backed out some from where you are now. This will allow you to slow the idle further. See my previous post for an explanation of why this is so.

 

Sweet pic. Do you grind the foot all the way off? How hard is it to take the pump apart to get to the spring and foot?

 

When you look at Den's pic, imagine the lever as a boot. You take the toe off the boot leaving a straight line.

It's about 45 minutes to get in if nothing fights you too hard. You'll want a helper for the actual R&R of the spring, it's kinda tricky if you have fewer than 4 hands.

edit: There will be a pic available soon. I copied Den's pic and did a little virtual modification to his AFC lever. When the mods approve it I'll post it to this thread. Thanks again for the pic, Den! Hopefully my voodoo AFC lever job gives you a few HP.

 

How much HP can you expect from the grinding mod?

 

My guess is around 30 HP. I did the spring, lever, and a hybrid turbo between dynos and picked up 50 HP. HP on a diesel comes from fuel, and the thing that added the most fuel was grinding the lever.

 

Cool virtual grind, Dave! I'll have to put in the 366 spring and grind the foot this weekend now that I'm thinking about it... Just how over-fueled will my baby H!C be now?!

g

 

I got a couple of questions, first of which do you need any special tools, and second, how do you grind it down do you remove it or just get in there with a grinder ?

 

wannadiesel, you rock dude!
So if I grind that baby totally off, I can (and should) back the fuel screw out? I have it all the way in now!
Do you have advice on how far I need to back it out? I'm guessing I will have to crank my idle back up to compensate. I hate trying to get to that jamnut!

Would grinding the fuel pin augment grinding off the AFC lever foot?

Thanks for the great help,
Mark

 

All I know is thank God for wanna, without him my truck would still be ssslllllooooooowwwwww. And from my experience listen to everything he says it will only make your cheeks hurt

Michael

 

I am sure that my pump has been turned up. When I really get on the accelerator sometimes it hangs and and th rpms keep climbing. To stop it I have to turn the ignition off. After I turn the ignition off, I can turn it immediately back on and it is fine. Is this a sign of what you were talking about with a fuel pump "runaway?" If I put the 3200 spring in my truck and grind off the AFC lever, should I turn my fuel down? Will I get better fuel mileage if I do? (I'm getting 16-17mpg right now.) Will turning the fuel down make my idle speed go down? Thanks guys for all the info. You have helped out alot!

 

Hey Dave, Why would the foot grinding cause the pump to possible not be able to pass the smoke snap test? Couldn't one just turn down the pump with the spring and foot grinding and pass? Could be an issue one day for most of us, especially in California

brad

 

efbeason, you should really back your full fuel screw out a little, I think your experiencing runaway.

 

You won't pass the snap test because grinding the foot essentially gives you more fuel with less boost. It's the same as moving the afc starwheel ALOT...I think. So...when you slam the go pedal...big black cloud. Here in Colorado, on the front range, we have to pass a dyno/opacity test. I've only moved the fuel screw in 2 turns and I'm pretty sure I wouldn't pass. I get the Piller of Cloud coming out of a stop if I romp on it.

 

Grinding off the foot is simialr to grinding a deeper notch into the AFC eccentric.

The foot is on one end of the "AFC lever" and the pin that rides on the eccentric pushes on the other end of the "AFC lever". So grinding the foot lets the engine have more fuel acroos all boost values. It is great at the top end, but you can't tune it out at the bottom . . .

You could modify the AFC eccentric and pin to correct this problem, but just grinding the foot puts you in smog control jeopardy.

 

Den is the guy who rocks, he took the pic!

fearthedeere - Use a small grinding stone on a Dremel tool. Make sure you pack paper towels up in the cavities above the lever to minimize the amount of grit and metal filings that get up there. After you're done with the grind, turn the pump top upside down and pull the paper out and spray a lot of carb cleaner up inside the pump top to flush any crud out. You want this thing absolutely clean when you put it back together.

Mark, if the truck isn't showing signs of runaway you can leave the fuel screw alone and enjoy the extra power. If it acts like efbeason's truck you need to back the screw out some. Grinding the pin (or adding an Old Smoky pin) will add even more power.

efbeason - you are on the edge of runaway. Back it down at least 1/2 turn. Grinding the lever will give you more power than you had before. In town mileage might drop if you have a heavy foot. Backing the main fue screw out will lower your idle speed.

Brad, what Tucker and Alec said about the snap test is right.

Alec, I have to disagree with you about being able to modify the eccentric to compensate for the ground AFC. At zero boost with a shaved washer the fuel pin is pretty much on the full diameter of the eccentric. Even with stock injectors the ground lever allows so much governor lever travel that you can get a puff similar to the start-up puff just by mashing the gas in neutral. That's not going to pass.

So again I say If your state has a snap test or if you know they will while you still have your truck, don't do this to your pump!You can still drive the truck cleanly, but heavy throttle application at low RPM will result in lots of smoke.

The best way to set up the AFC once you've ground the lever is to run the star wheel up as far as you can while still having the "clickers" engaged with the star wheel. Back the smoke screw out until it's flush with the inside of the AFC cover. Set the fuel pin in however you want, all we are trying to do is delay the AFC fuel as long as possible so it doesn't come on until the turbo is spooled up.