VE Pump fuel Screw only went 1/4" turn then stopped.

[CumminsPower]

This post is of course about the VE pump fuel adjustment screw. I will start with a little information about the application and the pump. The Pump is actually on an IH D358 Motor, it has a 12mm head just like the dodge truck application but it does not have the fuel control device on top with the AFC to limit fueling in low boost conditions. It looks like the pump was set to 150hp at the flywheel from the factory in it's application , which is probably somewhere around 80-100cc's of fuel. This engine was taken from a cotton picker and placed into a tractor that I pull with. I removed the collar that was preventing the fuel screw from being moved inward and ran a tap over the threads to clean them up, when I put the fuel screw back in, it would only go about 1/4 of a turn more than what it already was. I have read that there were also dodge trucks that had the same problem of not being able to adjust the fuel screw in farther, what have you done to give yourself more adjustment? I haven't taken the pump apart yet, but that is my next step, I need to get as much fuel from this pump as possible and will eventually get a 14mm head for it, but there should still be a lot of potential in this 12mm head. I am hoping to see over 300 hp with this pump, which according to the results on this board, should not be any trouble at all. I am currently running a hybrid H1c/H1e Turbo on the engine, but hope to go bigger as soon as I can get more fuel to drive the larger turbo. I am also looking for other mods that I can do to the pump internally or externally to get more performance out of it. I am going to pick up a 3200 rpm spring and put an electronic lift pump to supply it fuel (it is currently gravity fed, like in it's original app). I don't have a fuel pin to change or grind on, so what other mods am I looking at? I have read lots of info on this pump and will be tearing into it soon, but would like some more insight. My max RPMs will typically be 3,000.

Oh and I do have a Dodge/Cummins truck, but it pulls the trailer so I don't think I will do anything to it for now, it's got plenty of power.

[Ace]

Bosh PN# 1 463 402 423-000 is the fuel pin. I'd get a new one and see if it goes in any further. Then maybe try carefully adding an 1/8" or so to the tip with a welder. That has been reported to give more fuel.

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[CumminsPower]

I am not arguing I am just wondering what I will accomplish with the new screw. Right now it bottoms out before I run out of threads and the threads are good and clean, so something inside must be stopping it from going in any farther. I will pull the screw back out of the pump and double check but the last time I tried to adjust it, there were still plenty of good threads and it just would not go in any further.

[Ace]

Dunno. Either there's something different or wrong with the pump, or there's something different or wrong with the screw. Screw's alot cheaper and will give something to compare/play with. Just a suggestion.

[CumminsPower]

I will pull my screw and look at it again and just make sure that there isn't anything going on there. I don't think the screw in mine has the unthreaded portion in the center either.

Back when I first tried to adjust it and I could not get it to go in any further even after cutting off the colar, I started looking for info on the web and I found this:
"On a very few engines turning the power adjustment screw clockwise will not turn up the power. On these engines the injector nozzles must also be replaced with higher flow nozzles in order to increase power."

here: http://www.tstproducts.com/vepumpadjustment.aspx

And thought that possibly someone else had overcome this problem, I would love to just change out my current pump for one off of a cummins but the mounting plate on mine only has 2 holes (1 on each side) instead of 3 like the cummins application pump.

[CumminsPower]

I am going to try pulling the screw out and seeing if I can push a metal rod back in there to see if it will go any farther than than the screw will, that will tell me if the screw is the problem, if it is I will try the method of welding a little material to the end of the screw, to push the lever back in there farther.

[PToombs]

On the screw that Ace posted a pic of, the groove in the middle is where the sealing o-ring sits. It seals on a shoulder in the hole. If you tighten it too much it will damage the seal area, and will leak. Time for new pump top. If your screw is different, all bets are off. Try welding a little on the tip of the screw and try it.
I think I'd try the governor spring also and see how much that will give you.

[CumminsPower]

Thanks for everything so far. I am going to pull that screw this weekend and have a look, I will probably weld some on the end of it, if it looks like it will help. More than likely I will also pull the pump top to install a 3200rpm spring, which shoiuld allow it to fuel hard to my limit of 3,000rpms.

[CumminsPower]

Well I pulled out the fuel screw and got a longer one to go in there, but When I was trying to remove the top so I could replace the spring, I ran into a problem. Of the 4 bolts that hold the top on my pump only 1 of the 4 is a 5 mm allen head, the other 3 are flat heads. The 3 flat head bolts were very easy to remove but the allen head is almost impossible to get out, I tried and and it started to round the head out. I am almost certain that there is no way I am going to be able to get it out with the pump still on the engine. I took a slight larger allen wrench and filed it so it would fit tightly into the head again but it broke when trying to remove the bolt. I would try to heat the casing of the pump and remove the bolt, but I am not going to do this while it is on the engine because I don't want to start a fire.

Has anyone else ever had this problem and what did you do to remove that stinking bolt?

[921stgen]

You may try it when the engine is warm. I had same problem but probably not as tite and I used a hammer and LIGHTLY tapped on the top of the allen wrench and was able to break it free.

[TWorline]

If striking the allen bolts down inside with a punch and hammer don't work try one of the old strike type impact drivers you use with a hammer. They are invaluable working on old Jap bikes. The great thing is by hitting it with a hammer it keeps the allen end seated down in the allen head bolt.

[Darren A]

I am having the same problem with my fuel screw, I removed the collar and only got about a half turn out of the until it started to get tight, and I didn't want to force it.