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I have seen posts asking for info on the inline A pump
The following has been lifted from this site http://www.freewebs.com/nevrenufhp/index.htm
I take no credit for it, the article was done by nevrenufhp

To the rear of the pump on the top is 2 different allen plugs. The bigger one is the fuel rate, and the smaller is the star wheel, or pre-boost smoke adjustment.To do the fuel you take off the plug with either a 3/8" or 10 mm allen wrench. Now tie up the fuel shutoff sol. or pull cable in the run position and you will see the adjustment screw. You may need to put a brick or such on the accelerator to keep the screw in the right spot under the hole. Break the jamb nut loose with a 3/8" or 10 mm deep socket and loosen the screw all the way. At this point it will be loose in the rack, but not fall in. Take some needle nose pliers, or magnet retrieval tool and carefully remove the screw. Run the nut so there's 3-5 threads left on the screw(away from the head). Now (again-carefully) put the screw back in and tighten it with a regular slotted screwdriver up to the jamb nut. Then a good snug on the jamb nut and it's done. Note #1: if you get the screw too high, it'll hit the top of the pump and make the rpm stick. Run the accelerator and check to see that it wont bind up in there. Note #2: If you drop the screw inside the pump you can retrieve it easily with a pencil type magnet, and it's not that easy to get out. Untie the shutdown sol. and remove the accelerator weight tool. Under the smaller allen plug is the star wheel. Take the plug off with either a 5/16" or 8mm allen wrench. Spin the star wheel towards the front of the pump(rotate towards the pass side) to increase low end power(smoke)and away for less low end smoke(essentially releasing the tension on the spring inside). The governor spring mods, and accelerator stop screw are the same as the newer 466's described above. The timing advance is covered in the same article as mentioned above or here it is again: http://www.thedieselgarage.com/forums/showthread.php?p=235958#post235958

If someone out there is a brave enough person, try running withouth the fuel screw. I havent tried it, nor can confirm it wont cause pump/governer damage. I know some Cummins 6BT owners run with no fuel plate, that's why I thought of the no-screw on these.
 

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Now if I could just get a hold of some Isuzu 4 mods, besides the external screw, I'd add that too.
While the Isuzu has an A type pump, it's ultimately the governor we're adjusting. I've got internal pics of the Isuzu governor, it's not that exciting.

It's the torque plate inside which sets the rate of fuelling with rpm.
 

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So a 'reprofile' would alter the fuel curve then?:D
Bosch have various torque cams to suit the particular engines that the pump is fitted to.

So 2 options are: find an different torque cam, or change the profile.
 

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While the Isuzu has an A type pump, it's ultimately the governor we're adjusting. I've got internal pics of the Isuzu governor, it's not that exciting.

It's the torque plate inside which sets the rate of fuelling with rpm.
By all means, send me some info and pix!bounce :beer:
It's all just a reference site anyway, not like I make money off it.
 

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So a 'reprofile' would alter the fuel curve then?:D
Not sure if it is just like the P, but if so the gov. spring rate changes the arm travel up the plate which also effects the fuel curve. I know this because mine is kindof screwy with shimmed springs and a stock plate. It fuels real hard lower RPM and then gets a dead pedal where you get no more fuel untill it revs way on up. After finally finding someone to explain the whole deal I found I just need a plate and spring set matched for eachother. Most will say the fuel plate is all that matters for fuel curve, but this is far from true.

Dont get me wrong it is MUCH more fuel and power than stock, but it kindof stalls fueling around what should be the peak power point.
 

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So a 'reprofile' would alter the fuel curve then?:D
Not sure if it is just like the P, but if so the gov. spring rate changes the arm travel up the plate which also effects the fuel curve. I know this because mine is kindof screwy with shimmed springs and a stock plate. It fuels real hard lower RPM and then gets a dead pedal where you get no more fuel untill it revs way on up. After finally finding someone to explain the whole deal I found I just need a plate and spring set matched for eachother. Most will say the fuel plate is all that matters for fuel curve, but this is far from true.

Dont get me wrong it is MUCH more fuel and power than stock, but it kindof stalls fueling around what should be the peak power point.
nexxussian was referring to the A series I.P. that is fitted to the Isuzu 4BD1-T. The I.P. on the Isuzu has a type RLD governor, which is a different type of governor to what the 1st post referred to. Also much different to the type of governor on the P type I.P. turbos10 is referring to.
 
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