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fuel pump turn up???

82K views 26 replies 17 participants last post by  93Cummins250 
#1 ·
hi i was wondering how to turn my fuel pump up on a 1993 cummins 12 valve without having to worry about runaway>>>>and i want more smoke lol how do i do this myself thanks Aaron
 
#2 ·
the smoke screw will give you smoke without runaway. there is a round cover on top of the injection pump, take it off and there is a torx screw and a lock nut, turn it clockwise to turn it up.
 
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#3 ·
how far do i turn the torx down?? all the way
 
#4 ·
here's how i gave me truck "the biscuits" , popped the whole cover of the pump, carefully pull out fuel pin, turn it 180 degrees so that deepest part of the fuel pin is facing toward the front of the truck (you'll easily see what i mean), replace the fuel pin back in, now i also dropped the smoke screw 3 turns, but didnt touch the power screw on the back side, this will deliver more fuel on initial motor accelaration MAKING HER SMOKE
 
#26 ·
"The biscuits". Haha love it man

But get an aftermarket fuel pin, and turn up the power screw until you get scared or get runaway, then back it down.

My truck smokes like a locomotive if I want it to
 
#8 ·
I'd buy a fuel pin, like a denny T fuel pin. It will give you more power, smoke and top end! and its easy to install. They claim 40 horse and around 70 ft. lbs of torque by changing the fuel pin.
 
#9 ·
to really make it smoke you need to add more fuel. the adjustments they are suggesting will let the stock amount of fuel to be delivered sooner at lower boost. give a puff of smoke at take off. the fuel screw is in the back of the pump facing the firewall. hard to see but look above the fuel lines for a screw with a collar and a jam nut. loosen the nut and back the screw all the way out. now you need to cut the collar off without damaging the threads. use a file or saw, your choice. put the nut back onto the screw all the way and put the screw back in. i run mine screwed all the way in until it bottoms out and leave it there but i hear about runaway on here all the time. most guys turn it until it bottom and then back it out a couple of turns. you will need to adjust idle. i ran with my screw bottomed out for 130k and my pump gernaided at 250k. i had to replace the pump and the first thing i did was bottom out the fuel screw. that's been 50k and still no runaway. lucky??? this will make the smoke roll. rotate the pin and while your in there with the pin out you will see a gear looking thingy in there. turn that a turn or more for more smoke. that's the star wheel and mine is turned all the way down "clockwise"
 
#10 ·
hey guys,
i have owned one 0f my 93 trucks for about 1 and a half years, it has always seemed a little doggish. I assumed that was because it has 258,000 on it and the previous did not know anything about diesels and did not take care of it. I hauled a load of wood today and had to shift into 4 lo to get it goin up the hill. The load was ot that heavy. My question is how do i give it a little pep without breakin the bank?
 
#13 ·
i have turned up my ve pump today. I could only get 2 and 3/4 turns on the smoke screw. I then tried to turn up the fuel screw 2 turns but it became extremely hard to turn so I backed it off to 1 turn. the truck then started to stall as if it couldnt get fuel. it runs it just chugs bad now. Did I do somethong wrong? this is the first time i did this so i could realy use some advice.

12valvemafia
 
#14 ·
i personaly have no experience with a aftermarket converter but ive herd that dtt, suncoast, and goerends are the best.

im ordering a goerend for my truck soon

they cost anywhere from 600 to 700 dollars
 
#15 ·
goerends all the way!!!!
 
#17 ·
ebay is where i got mine, that was the cheapest i found it. And if you put the 366 spring in, might as well take the afc lever out while your at it, I just did that and i like it. Then you can run your stock pin still and have full fuel all the time. I would take the afc lever out and send that bully dog pin back. You'll get more power by doin this than puttin that bully dog pin in anyway. Plus the bully dog pins get a goulge in them after a while. Trust me, I used to have a bully dog pin and then i sold it. It had a little groove in it from the needle that rides on it when i sold it. They are made of soft metal. Just thought I'd let ya know
 
#19 ·
look in the VE Tech articles. Thats where I got a good idea on how to do it. I would've taken some pics and made a thread when i took mine out... but it was a mess... and I have red fuel :confused013:in my pump at the moment, so it wouldn't look so good...:hehe:
 
#21 ·
i did all that with the smoke screw but i cold only get 1 turn on the power screw on the back of the pump. Also what would be a better initial investment guages or injectors. keep in mind the truck has 260,000 on it
 
#23 ·
Turning the smoke screw really doesn't add power. It can make the power come on earlier by pushing the fuel pin down which allows fuel to turn on faster helping to eliminate turbo lag. This also adds smoke as the fuel hits before the turbo gets spooled up.

With my setup I have the smoke screw backed out all the way to try and reduce smoke - still smokes like crazy!

12valvemafia, you said you turned the fuel screw and the truck tried to stall. Make sure you are on the fuel screw and not the idle screw. They are both on the back side of the pump.

The fuel screw has a collar welded on to keep it from turning too far. You should be able to take it to the stop without a runaway. SHOULD is a big word here! Always that truck that will make an exception to this statement. You can remove the collar and get more fuel but this is usually where you can have the runaway problems. Have the intake line loose so you can slap a piece of plywood over the intake hose in case of a runaway. If you get a true runaway, the manual shutoff lever will not shut the engine down.

Turn the fuel pin in the AFC to the deepest point for more fuel. This is what the modified pins do only more than just turning the stock pin. The deepest section of the pin needs to face the front of the truck.

Turning the starwheel down reduces the pressure needed to allow the boost diaphram in the top of the pump to push the fuel pin down allowing the pump to provide more fuel. Raising the starwheel up does just the opposite and delays fueling. I usually run with the starwheel all the way down for racing or Dyno runs and raise it back up for normal driving. I have way too much smoke and need to do something else to reduce it cause I'm going to get a ticket one of these days. I don't drive it much anymore because of this.

Bump the timing up about 1/8" above the stock timing mark and this should put you somewhere between 16 and 18 degrees timing.

If you are turning stuff for the first time, count your turns on everything and write them down so you can go back to them if you need to. Mark the top of the diaphram the fuel pin connects to with felt marker so you know where the stock location is.


AND - before cranking the fuel up too much, get a EGT gauge and boost gauge do you know what the end effects are and to be sure the EGT's stay within reason. You also will need to watch the fuel pressure from the stock lift pumps if you crank up a lot and install big injectors. I could drop the pressure to zero on the stock pump and to about 4 psi on the first gen piston pump. Thanks to BBRam, I have a FASS pump I need to install that should take care of my pressure problems.

Hope this helps a little. Don't be too afraid to turn it up, just keep track of what you are doing and you can always go back.
 
#24 ·
Ok so I've taken my pump apart twice before I just didn't have time to deal with the smoke wheel. So I did have enough time to tinker with it and I've read all the forums and watched all the videos on it and I'm just kinda tired of no smoke while my dads 97 with the P pump smokes like a freight train. So I went to hop to it and 1 of the 4 screws holding the top of the pump together was being stubborn and would not come out. I burnt up all the time that I did have set aside and I had to give it up for that day. I was hoping maybe it was just that day and maybe the ridiculous shaking may help after a while. So I was just out at the truck and it still won't break loose. Is there a trick to busting it loose? Is there something I can use to do it? I wouldve thought maybe it was rusted in but like i said i have had it opened up for operation twice before so idt it should be locked up as ridiculously tight as is it. Now, a separate question; the reason I didn't mess with it when I first had the pump apart was because my starwheel has something on it that keeps it from backing back out. The starwheel doesn't turn either way like its stuck and I've not heard anything like that from anyone else...do any of u know what I'm talking about and what I can do to fix that?
 
#25 ·
If you want smoke put a plastic bag over your air filter :confused013:
 
#27 ·
Bag on the filter or fill the bed with tires and light them on fire and stay in the burning vehicle. Purposely making ur pickup smoke is what gives the diesel crowd a bad name and horrible reputation smoke is wasted fuel and does no good just a sign that it runs like crap and the owner is probably to lazy to properly tune it or a douchebag who thinks hes cool cuz he can roll coal on people and do other idiotic things
 
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