First I would like to start by saying that I am not new to diesel engines however I am new to the 7.3 idi non turbo. Ihave spent most of my time working on PSD, caterpillar, and cummins in service trucks and tractor trailers. So here comes the question. I am aware of the ip modification in which you turn in the the fuel metering screw located behind the window on the pump but one of the fellows that I work with told me that there is another adjustment located within the fuel inlet on the stanadyne pump. Just curious not sure if I am willing to perform if suchan an adjustment is possible. Also here is a list of mods I've already performed. Custom cold air intake connected to functional cowl induction hood, 3 inch dual exhaust with x pipe in to 5 inch grand rock aussie stacks, dual pyro's (one in each manifold) oil pressure gauge, oil temp gauge, water temp gauge, trans temp gauge, and I even went as far as to place a oil temp gauge in the differential dad always said anything worth doing is worth doing big. Anyway I chose an idi because I worked on PSD's and believe this to be a more durable platform and so far I love this truck. I would appreciate any info on this subject and look forward to maybe one day being able to lend a helping hand myself.

 

I've heard of an adjust ment simmiler to this, a teacher I had at an international training course had an old olds diesel with the gutless 5.7 he had to change the injection pump on it when he put it on he noticed a scwer sticking up in the fule inlet so he screwed it in he said it ran like a striped a$% ape and blew tones of black smoke. any ways I belive tats the fule screw on the older styndynes? that were used on those engine not sure if the DB2s have them.

 

Thanks wasn't sure if anbody else ever heard of this. If it helps someone come back with afor sure answer the truck is a 93 ext. cab longbed non turbo. I'm sitting here looking at my siesel fuel systems manual and looks like there is an adjustment but am still wondering if anybody has ever played with this.

 

The screw in the fuel inlet set the transfer pump psi. Increased transfer pump psi pushes the plungers and rollers out further agaisnt the leaf spring, increasing fuel. This will also affect the advance curve of the pump which is adjusted by fuel psi.

Looking in my Stanadyne book it says transfer pump psi is not to exceed 130 psi.

 

so the DB2s have it too? would there be any advantage to adjusting it this way over adjusting the alen screw in the window and turning the pump for timing?

 

george d I am still unsure if this is a viable adjustment for power or if it is all hear say. As I said before my expierence with mechanical diesels is limited to mostly bosch style pumps and pt cummins. So lets see if anyone else at there can respond with some good usable information for those of us still wondering. As I said before my diesel fuel systems manual shows something there but has anyone torn one these things apart and can verify that it is indeed there. I may experiment some today and get back to you all.

 

By the way thanks chris1066 for the info right now I can use all I can get. These stanadyne pumps are spanish to me. Do you know how the increased fuel pressure effects timing ie. advancing or retarding. Thanks again.

 

I don't have a lot of experience on the automotive pumps just whats in the manual I have. I have had a few apart for seal kits but they were ag style DB2s off of older IH 460 / 560 tractos. They have a different hydraulic head and fuel inlet. The rest of the pump is very similar.

I not sure how much or how far the timing would be affectived. If I rember right the timing advances as fuel psi goes up. I say this because as rpm is incresed so is fuel psi, and the timing shuld adjust acodingly. So if you up the psi you should advance timing to a point.

I think before I would adjust it to much I would try and find an adapter and hook a guage to see where your psi is now.

I have heard of this mod done on tractors before but am unsure of how far they turned it up.

You could also remove the shims under the leaf spring screw but that requires the pump be dissasembled.

I hope this helps for now. I am sure that there are others that know some more on this and can help out.

 

chris1066 Thank you for time and your resources as I said before I haven't much experience with stanadyne or roosamaster or distributor type ip's. All my experience is with bocshbased pumps as well as pt cummins and the later hydraulic high pressure di stuff on cat and psd's. You're info is greatly appreciated and your time even more so. I have cranked the fuel on 3406 and 3408 cats as well as 855 and n14 cummins but never messed with rotary pumps. So how bout it anyone out there ever tried this.

 

The pump I have on my truck now is off a 94 turbo diesel and a buddy of mine rebuilt while he worked at a pump shop. I had him leave out the shims and am getting enough fuel by tightening the leaf spring screw. It is what actually adjusts the fuel delivery on this pump.

 

This Is part of the instructions on the ATS install instructions.

"On serpentine belt model engines (l992 l/2 and newer)

adjustment of the torque screw alone should provide

sufficient fuel delivery in most cases. Turn the l/8" allen

screw counterclockwise 4 turns out and tighten the lock nut."

What screw are they referring to. Is it the one in the middle rear at the bottom of pump, or the one at the upper rear on the drivers side?

 

So the adjustment that we are discussing actually just increases fuel pressure to the high pressure side of the ip pump and does nothing to the actual volume delivered. I am planning to rebuild this pump in the near future and from what I gather it would be a BETTER idea to modify the pump internally than to mess with external adjustments. I aquired a tech manual on thedb2 pump from work today and they seem fairly simple to modify luckily I have access to a machine shop aswell so no big money spent on custom parts. Anyway would you say that I am right in my assumption I hate the idea of having to turbo this thing and was just looking fo a little more free power if sucha thing exists in this day and age.

 

You are correct the adj only affects the high psi side of the pump not actual fuel delivery. If you take it apart pay attentin to how you dissasemble the transfer pump and also the camring. They can be installed backwards to be used in other applications where the rotation is the opposite of our Fords.

If you do not have a turbo I would'nt worry about the shims. Just tighten the leaf spring a flat or two and see what happens.

The torque should be the upper one and it limits how far the metering valve can open.

Its nice to work on somthing where you can turn a few screws and gain some power without having to spend $$$ on programers and chips.

Has anyone had a 4 roller pump built for a 6.9L. Just curious if it's been done before. I think it would be neat to try somtime.