No More Rolling Coal: Tuning a P-pump AFC 

My first time adjusting a P-pump! Go ahead, roast me in the comments OR let's hear suggestions for my next attempt at tuning this thing!

Thank you for cleaning up the Exhaust. Rolling coal is pointless and not cool anymore

"Rolling coal" is just plain stupid. Thanks for posting a great video on properly tuning the P7100.

Nice detailed video and adjustment descriptions that you went through to get the truck to where it ran best for you. I've never messed with a P pump before either, and your descriptions will help me know where an approximation might work from my Step Van. I have not seen any other video out there with adjustment descriptions and video. You did an awesome job, and thank you very much for taking the time to post this video!

Great video! Thanks for the in-truck view of things. Very helpful!

Thanks for doing this. I'm new to the p pump cummins and appreciate your time.

My favorite way to tune the star wheel with a stock hx35 is by removing it and applying regulated shop compressed air at 35 psi to the afc. Then adjust the star wheel as needed to get full rack travel at 35 psi of boost.

Much better tuning. Truck looks like its runs great and right now. Great Job Tim!

This was a great video. This applies to my 12v 5.9L Cummins and my VW 1.6td idi engine too. (both VE pumps)

This was very educational for me. I really have been wanting to get rid of the excessive smoke on mine. Thought I had to buy a bigger turbo but really not ready to order it. Will try this instead for the time being

Just wanted to say thanks for doing this. I haven't adjusted my AFC yet either and was wanting to see something in truck as opposed to on bench.

I really miss my crew. Should have never sold it but life is what it is. Great video. Had to subscribe. When you do the GSK make another video.

I’m gonna try your way to tune my 95 12v cummins so I can get max power without bogging the turbo or dumping smoke. I’ve been messing around with it but I can’t seem to figure out just the right combination of smoke screw and star wheel. Thanks for the good video.

Set of the LMC Truck door seals arrived this week. They definitely look good, will let you know how they fit/function after the install.

Great video. 👍

Great video, I learned something I didn't know that I didn't know 👍

Good video. My 97 is over fueling bad. Not sure who was into it over the years, but constant smoke. Planning on seeing what I can do about it this coming weekend.

Great video. Appreciate the info. Alot easier to tune a 12 valve than I thought. Putting one in my F350 once the 7.3 decides it needs a major repair. At 317K miles it's anyone's guess how long it will last. Seems to run ok, but we will see. Already have the full conversion kit to mate the 12 valve to the ZF6 manual.

I remember this video .. i many years ago wanted to help my truck it got poor mileage and just seemed lacking in power . So i finally after everyone saying O will burn a hole in the piston. I gave the engine timing the mileage went from 16 to 21 on the highway . 17.5 deg or close to that timing . Power i installed a 10 plate all the way forward. The AFC all the way forward. Gave it some preboost . 3 k governor springs.. 215 injectors..i got them from Piers in Canada . Believe it or not with a automatic i could drive it with a lite foot and it did ok . . But when i installed a g56 things got worse . I finally got tired of the smoke very quickly.. Cruise control was a pain in the butt on hill as the cruise will give the truck more throttle . ..So i orderd the spring kit for the AFC and installed it .i then started adjusting the star wheel back . The truck seemed to run better but it would stll smoke pretty good .. i adjust the pre boost back also ..Finally after a few attempts the star wheel , i loosen up the AFC house and slid it all the way back . That finally got the smoke under control. Still runs good ..shifting through the gears is good . I can if i want make it smoke a bit . But for me its a lot better to drive . . I dont care about high end hp . I just want smooth power and not deal with people. Drama , smoke ..To be honest its still a lot better than it ever was stock .. .

Thanks Tim

And this episode sponsored by Sonic drinks 🤣 Yeah, no more depends! Keep up the good work Tim, you help a lot of us.

Hey I’m diesel tech and my personal truck is a 1997 12v and a few mods I would recommend would definitely be a #10 fuel plate for less low rpm fuel , also I would recommend a new afc spring that is longer I believe the one I put in my truck was from bd diesel and it lets the afc have more travel and a smoother ramp up of fuel with boost

Much obliged

Dude!! Fantastic video. I am professor that loves tinkering with my Jeep with a 4BTAA. I get very frustrated with videos on these mods in a lab/bench. Are you kidding me?! How do you tune or adjust these on a bench? How many 4BTers are modifying 4BTs on a bench? The vids I have seen will inform the viewer how and that is it. As a professor, in my discussions and teaching, if my goal in teaching is start with answering the "why" with the "how" I am successful. I have failed if I don't and students will not get the understanding they need. You did a great job in explaining how, but including the answering the "why." Few RU-vidrs do this in their instructional videos. There's several books on this. First one is titled: "Start With Why, by Simon Sinek.

I got mine tuned to just about perfect for best fuel economy while towing a gooseneck with 30k on it, got a 100 plate and 30 psi of boost, I’d love to be able to turn it down tho for when I haul my 5th wheel and then just drive back and forth to work… I think afc live is in my future lol

I bought a 2nd gen 12v with an s400 and 150hp sticks. Thing smokes like crazy 3rd gear on with light throttle. I haven’t tried adjusting anything yet bc it does run good, but I think it needs some fine tuning

exactly how I did my 8.3 in DP now it pulls mountains dragging 33k lbs up no problem.When I got it years ago it would handle steep mountains but barely get up them at 55 . Once did the 75hp throttle plate kit and tune I had no issues holding 65 up and feel it would even accelerate to 75-80 with no problem. I do try to hold around 60-65 to maintain Low EGT temps with 12mpg because even at 70 it drops off 10 mpg and 75-80 about 7mpg With the pump mods. Runs like I am driving a pickup and have to set cruise on long drives or I would often end up past 75 not even meaning to as I followed Trucks.

Smoke definitely makes horsepower. I just turned mine down to not smoke. It’s slow af compared to how it was. I could spool 45+ psi through my S366. Now it struggles to go over 30. Turning it back up after I’m done traveling.

I need those seats and center console!

may want to slide the afc housing and adjust the star wheel from there seems like it would put less pressure on the spring

I love you bro your awesome

35 psi of boost is the magic number for performance and efficiency with a 12v and a stock hx35 turbo

AFC position also matters. My AFC is slid all the way forward the smoke screw is backed all the way out and it still makes a decent cloud down low.

Hello, I'm from Germany, why do so many Americans love to let their trucks soot? Greetings from Germany🤗

You don’t need a lot of preboost screw, only about .5-1.5 turns past contact with the screw. Any more will make the idle mixture too rich and it will run too rich till it spools the turbo.

Need to work on my VE tuning. First need to adjust valves as they are a bit clanky.

Great Video, one of the simplest on setting up AFC. So many just say "everything full forward!" without a thought to how it all works. Simply getting the preboost dialed in on my truck resulted in better fuel mileage; going from 13 mpg to 15 mpg, mostly city driving. I adjusted mine similar to your method and it's now a blast to drive. Throttle response is so reactive, surprised how little it takes to get moving. I can even cruise @ 65mph with just the weight of my foot on the throttle. Then lean into it and gobs of power on demand. Considered the AFC live, but once you get the AFC dialed in, it's pretty good for most scenarios.

Do I need to mess with my star wheel if my truck is only Rolling coal pre boost? Or do the smoke screw and star wheel work together so if you adjust one, the other will be off adjustment?

So the smoke screw could use adjusted if the engine has a hard cold start issue, even when it’s not very cold, just sits overnight?

My p pump 12v doesn’t smoke at all no matter what. I wish it would smoke like yours, but only when I really want it to. Are you not running a fuel plate? I have a 100 fuel plate in which is one step below a 0 fuel plate.

Power driven diesel makes a afc live kit for p pumps

Egt is best way…only way to know really.. at 20 psi I like 1000 max at full send 1200 1250… with haze u got now it’s too hott for sure

N o matter what I adjust,the only way I hear the turbo is air cleaner 90 pipe removed

Put AFC LIVE on it from Power Driven Diesel

Do you have a fire alarm fan in your family?

Greta thornberg approved this message

annoying watching first-timers fiddle around, just put a AFC live on it with a long travel kit on it, then you can fiddle around all day long without having to even pull over. lol. also for adjusting the star wheel, hook it to shop air with a gauge on it, adjust it so it starts moving at about 15 psi depending on your turbo set up.

Why would you not want to roll coal? You need the option to roll coal so you can roll coal on teslas. 🤦🏻‍♂️

Soooo all the truck and tractor pulling guys are doing it wrong? Smoke obviously = power, the millions of truck and tractor pullers are NOT wrong!

Look on DAP diesel thry have a afc spring kit get the springs thry are longer and will work alot better and set the star wheel all the way down. Idk how we can go about it but you can contact me and I can help you more