Thanks Thanks:  1
Likes Likes:  2
Results 1 to 9 of 9

Thread: (How to) turn up your p-pump

  1. Top Of Page | #1
    Basic Member

    User Info Menu

    (How to) turn up your p-pump

    I won't go way in depth here but I'll give a few pointers on how to do basic mods to a p-pump.


    First of all there's your fuel plates. Now you have some options but stock trannys n clutches won't handle much more power then stock. First off you can slide the plate forward it's like a 30hp gain n should be okay on the stock tranny or clutch. Next you can grind your plate down or get a aftermarket one. Almost all diesel performance sites can get them. But again stock tranny n clutches won't handle the power, Or you can do like myself n say in the trash you go n toss the plate all together for a 150hp increase.


    I will add other things to this on a later date probably tomorrow I'm just tired.


  2. Likes CiscoDad liked this post
  3. Top Of Page | #2
    JOKER! F350Cummins's Avatar

    User Info Menu

    Please so one way in depth and I will make it sticky! That way we can just send people to look there when they ask.

    2014 Ram 2500 CCSB Ram Box Larime
    2011 Ram 5500
    2006 Diesel Jeep Liberty
    RIP. 2016 Tradesman 2500 picked up 9/28/16 MM3 DRD Tuning 107K miles wrecked by jeep wrangler.....


    Other Toys: 1973 Charger Bougham edition 400 big block 42K original miles
    Unicycles (about 3 dozen)


    6 in a row makes her go

  4. Top Of Page | #3
    Basic Member

    User Info Menu

    Alright that I will.


  5. Top Of Page | #4
    Basic Member

    User Info Menu

    Alright that I will.


  6. Top Of Page | #5
    JOKER! F350Cummins's Avatar

    User Info Menu

    I was going to do it, but i have to install a pyro and boost gauge first. then as i do it write it up. so i wont get to it till spring

    2014 Ram 2500 CCSB Ram Box Larime
    2011 Ram 5500
    2006 Diesel Jeep Liberty
    RIP. 2016 Tradesman 2500 picked up 9/28/16 MM3 DRD Tuning 107K miles wrecked by jeep wrangler.....


    Other Toys: 1973 Charger Bougham edition 400 big block 42K original miles
    Unicycles (about 3 dozen)


    6 in a row makes her go

  7. Top Of Page | #6
    Basic Member

    User Info Menu

    Okay sounds good. Just need a lil free time here soon.


  8. Top Of Page | #7
    JOKER! F350Cummins's Avatar

    User Info Menu

    pics are great too if you have time, if not i can add them later also

    2014 Ram 2500 CCSB Ram Box Larime
    2011 Ram 5500
    2006 Diesel Jeep Liberty
    RIP. 2016 Tradesman 2500 picked up 9/28/16 MM3 DRD Tuning 107K miles wrecked by jeep wrangler.....


    Other Toys: 1973 Charger Bougham edition 400 big block 42K original miles
    Unicycles (about 3 dozen)


    6 in a row makes her go

  9. Top Of Page | #8
    Basic Member

    User Info Menu

    I am getting to the point where I don't have the time to write it up now so I'll cheap out n post this from wikipedia I think.

    Let's start with gov arm adjustment. Now maybe I'm just reading too much into it but I set my gov/plate contact with the engine running at idle with the AFC cover off. Why? I got to studying the stock plate and with the engine off, the common knowledge is to set the lever where all the cutaway images show....BELOW the big protrusion on the plate. Then I got to wondering about how that arm is smoothly going to ridse over that protrusion. So I looked at my 100 plate conmtact with the arm at rest (solenoid in run position tho) then fired up the engine and checked it again. The lever won't swing out until you lightly stab the throttle, but I noticed that the arm contacts the plate a lot higher than at rest. We can only attribute this to gov springs acting on the gov arm. So rather than set the plate with the engine off, I run it and set the plate to the arm with the enginre running. The difference in arm height is about 1/4 inch...coincidentally about how much higher the arm would have to be to clear that protrusion on the stock plate. So my belief is that when running, the arm starts on the protrusion and not below it as it would seem. Now not many of us are running stock plates, but the theory applies anyway. I have never had to adjust my gov arm to a plate.....except maybe the "0" I was running for a while. Now I'm not passing this along as gospel, or to shake the foundations everyone swears by, but if you car to dabble, have a go at it and see what I mean. While my engine is off, my arm will swing under the plate, but have never had it bind underneath...this is proof to me that my theory is correct. So if you're setting the bleeding edge, maybe setting the arm on the nose of that pointed plate would be better done while the engine is running.....and hopefully you can get the plate where you want it without adjusting the arm any!!

    Next for the AFC.....several adjustments there, but not everyone understands them completely. At this point we know that the AFC is there to limit fuel supply during low, or no boost conditions. That's itsa only function, cut and dried, don't let anyone tell you differently. With a stock spring, after about 6 psi, no more AFC influence on the pump...that simple. If you have low tension springs in it, cut that down to about 2 psi. We know that the AFC lever protrudes down into the pump cavity right next to the fuel plate, and at no or low boost, it catches the gov arm and limits fuel that way. So what are we doing by moving the housing forward? We are simply moving THE ENTIRE ASSEMBLY farther to the front of the engine which allows the gov arm to travel farther which allows more fuel....that simple. So what about the star wheel? That wheel acts on a spring that pre-loads the pressure diaphram which is boost controlled. If we turn the starwheel towards the engine, it moves forward, releasing spring pre-load on the diaphram. As this pre-load goes away, it takes less boost to act on the diaphram and move the AFC lever out of the gov arm travel path. We think of these as the fine and coarse adjustments for the AFC, which is not totally true. The coarse adjustment is indeed moving the housing itself. But the fine adjustment is not the starwheel.....it's the so called smoke screw. You don't see this becasue it is on the back of the AFC housing under a sealed cover with a break off crew. This screw actually bottoms out on the diaphram center...from the boost side of the diaphram. And what happens when we add boost? The diaphram moves the AFC lever out of the way right? So by screwing this stud in, we give the lever a head start getting out of the way...much like moving the housing. That is why it is truly the fine adjustment. So we can set the housing in one position, then fine tune that position with the smoke screw. These adjustments alone will influence off idle smoke....not the star wheel. The star wheel will influence how long it takes to come off pre-boost fuel and into full fuel. So lets tune a pump...

    We buy a truck and the previous owner moved the housing forward, cranked the starwheel fwd and didn't even know about the smoke screw...so it's in it's stock position. The thing smokes off the line like a freight train and bogs like crazy...then when 6 or 8 psi comes around, it surges with power and breaks all the tires loose....that darn turbo lag right? Now let's tune the afc.

    Start by getting the access to the smoke screw...take the AFC off and remove the break off screw and smoke screw cover. Loosen the smoke screw lock nut and back out the screw several turns until it feels loose. Now screw it back in by hand until you can "JUST FEEL" the screw bottom out on the diaphram. Snug up the lock-nut a little and now set the AFC back to a middle position on the pump. Take out that hex plug on top of the AFC and bring the star wheel back from full forward about 3 full revolutions and put the plug back in. Now we have a starting point. Put her in gear and nail it. Do we have any smoke? No? then adjust that smoke screw a little at a time until it "just hazes" on take off. If you can't get that, loosen the smoke screw about halfway back out and reset the housing .020 farther fwd or so. Now try it again. Still no haze....adjust that screw in to get it. Or did we have too much smoke? back the screw off until it clears a little. You get the idea right? Any more than a slight haze off idle and you're wasting fuel, and maybe even hindering spool-up by quenching the cylinders with excess fuel and "puting the fire out" so to speak. So let's say we got the off idle launch looking good. Now it launches good but it takes too long for the turbo to come to life and the smoke goes away but no boost and it's laggy. That means we need to lessen the diaphram preload with the starwheel. This will hasten the curve out of pre-boost fuel control by allowing the diaphram to move with less boost pressure. Keep adjusting the wheel until there's a slight haze while you gauge shows less than 6 psi or so. If you get too much smoke once your RPM's start to climb, but before 6 psi or so, cranking the starwheel backwards will limit the fuel, cut the smoke, and smooth out the power. It's a balance game between the 3 adjustments....initial fuel delivery vs. building boost without quenching combustion. You'll know when you're right on....it'll launch hard, won't smoke, and boost climb will be smooth and rapid. These adjustments pertain mainly to the tune conscious driver, who wants drivability no matter who climbs behind the wheel, and isn't fueling for a funny car.


  10. Thanks dmuney thanked for this post
    Likes dmuney liked this post
  11. Top Of Page | #9
    Basic Member dmuney's Avatar

    User Info Menu

    Re: (How to) turn up your p-pump

    Has anyone made a complex or complete p pump tuning post or thread?

    I’m getting ready to do one myself


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •