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Can Someone Explain Some Pump Terms To Me

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Skyjacker rear spring problem

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I have done a search in the archives, but I keep seeing the same terms and I do not know what some of them are. I am looking at tuning my pump some more. I have adjusted the smoke screw my self so I am familiar with that. I think I know where the fuel screw is. It is on the backside of the pump close to the block. It is a long threaded shaft with a slotted head and lock nut. Am I on the right track? If so how do you adjust this one? Also what is this star wheel I keep hearing about? I am getting about 19psi boost right now out almost a stock motor. What can I do in my garage to help my fuel delivery and something a diesel novice can do. Also how do I get to this Dave Fritz web page? Thanks in advance for putting up with all my questions. Bill
 
Thanks for the link. Accepting the fact that I probably sound stupid, let me ask this. Is taking the diaphragm cap off and adjusting the star wheel and the pin as easy as it sounds? I am just afraid I am going to break something and not have the money to fix it. I am a diesel novice. Gas engines I can handle anything. If I do put something back together wrong will it still start and run and just not act right or will it not start at all? What is the best method for turning up the power and smoke? Turning the star wheel, the full load screw, or both? Thanks for everyones help. Bill
 
I haven't played around with any of my pump settings. I don't have my gages installed yet. So the question on can anything go wrong. I can't answer with any experience. But remember Mr. Murphy can be a very annoying fellow.



In your sig I see you haven't installed a pyro yet. I wouldn't want to do much on the fueling till you get one installed and get a base line setup on the truck.
 
I have read Dave's site about 4 more times and things are finally starting to make sense. That is a lot of info to take in when you first read it. I am definetley going to install a pyro gauge before I do any tuning. I have my mount and boost gauge installed already, just waiting on my pyro gauge from TST. I do have one more question about the eccentric pin. Does it just pull staright up and out to get to the star wheel or does it have something holding it down that you need to loosen? Also what is a good EGT to have before turning up my pump? I love this site. I have learned more in the last 3 days then I have in a year owning this truck. Thanks guys, Bill
 
From what I have seen posted around here. Most of the first gen's in stock form only run around 600 to 800 degrees on EGT. That is if all items are working properly.



But with all industry's using the" to meet production demands" syndrome. You never know what you have untill you put gages in it.



I have been to Dave's site many times. I am supprised I haven't had a box jump up and say go away your using to much bandwidth. LOL
 
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As far as EGT goes it depends on whether you take the reading pre or post turbo. In my truck I have the thermocouple installed in the exhaust manifold. I believe this gives you a more accurate reading of the temperature in the cylinders. The pre reading is approx 300 degree higher than the post readings. My understanding is that 1250 degrees is safe. In normal highway driving I see temperatures in the 600-800 degree range.

Cheers,

Al
 
This is only my opinion but I think the only place to take your pyro readings is PRE-TURBO.

If you use post-turbo then you actually need to do math to get close to your temps readings... . add 10*F for every 1 pound of boost ... until you get up around 22-25 psi, then that is too low and you should be adding more per pound of boost. Way too much work... . been there done that...



As for the AFC/starwheel/cone etc. When you go to remove the diaphram you will need to gently tug up and down on it a bit to make the fueling pin inside, pop back into its hole, out of the way so the diaphram/cone can be removed.

Once its out, remove the spring too. You should look closely at the cone on the bottom of the AFC shaft. You will likely see a shiny "witness mark" were the fueling pin has been riding up and down. This will tell you if your diaphram has been running at/on/near max or min. Look down into the hole the cone came out of. You'll see, down near the bottom a little hole on the left side, towards the front of the engine. That is were the fueling pin comes out of. If you cycle the thottle lever now, that pin should/will pop out. If it does then it is working ok, and you can use a small flat blade screwdriver to push it back in.

See the starwheel?? turning clockwise will ease pressure on the spring/diaphram and allow fueling to happen with less boost... turning counter clockwise increases the pressure on the spring/diaphram and make the pump wait for more boost before lowering the AFC/cone and starting the fueling. This can affect your EGT's alot depending on how far you turn it.

The 'full fuel screw' is on the back of the pump as you describe. It has a 13mm locknut. Use a spring loaded center punch to mark the little 6mm slotted screw end. That way you'll know were you started... loosen the locknut (13mm deep socket) and turn the fuel screw clockwise (top toward engine) to increase overall fueling, and counter clockwise to decrease. Tighten locknut.

Remember this adjustment sends fuel to the full power band,,,, BUT, a larger portion of that increase is directed towards the lower/mid range than the upper end. This will affect EGT's and mileage a fair bit. Oh ya, and smoke too !!!

Here's a link to a picture I drew one night when I had way too much time on my hands.

http://216.235.147.117/forums/showthread.php?threadid=19239



Hope that helps a bit...



Bob.
 
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Originally posted by farmall

I think I know where the fuel screw is. It is on the backside of the pump close to the block. It is a long threaded shaft with a slotted head and lock nut. Am I on the right track?



I haven't seen anyone address this yet, so I'll answer this one. The threaded rod is not the fuel screw--it's the idle speed adjustment. If you look closely at it you'll see that it acts as a "stop" for the throttle linkage.



Getting the locknut loose the first time can be interesting if you've never done it before. Some have been successful with taking a hammer and punch to it, but that didn't budge mine. What worked for me was to take a 10mm combination wrench, almost laying it parallel to the threaded rod, with the open end on the nut. Then you take a screwdriver or something similar, stick it through the other end of the wrench, making almost like a T handle with it. The screwdriver will give you the leverage you need to break the nut loose. Sorry, I know that's not particularly clear--if I had a digital camera I'd set up my tools, take a picture, and you'd be able to see instantly what I was talking about.



Mike
 
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