Stanadyne DB2 Injection Pump Throttle Valve O Rings Replacement: Throttle Shaft Removal?

[Crapgame]

Application: Stanadyne DB2831-5149 Injection Pump on 1995 M1025A2 6.5l NA

Fault: Throttle valve leaking diesel out the driver side when vehicle reaches warm idle speed, diesel pools up in the gallery between cylinder heads, cascades over the transmission bell when vehicle accellerates, diesel destroy the asphalt end of my driveway and is a moderate fire hazard.

Corrective Action: Replace Throttle Valve O Rings Stanadyne Part 24585 SEAL, Throttle Shaft; and Part 14408 WASHER, Throttle Shaft Spacer

The Stanadyne factory disassembly diagram shows a C clip holding two halves of the throttle shaft together inside the top housing.

The TM 9-2815-237-34 Direct Support & General Support Maintenance 6.2l NA, 6.5l NA, 6.5l NA Detuned, and 6.5l Turbocharged Engine Jan 1996 edition

Thanks to a previous Injection Pump thread with the identification of the T-25 5 point tamper resistant screws, I ordered both a fixed screwdriver as well as a 3/8" drive T-25 5 pt tamper resistant bit. Of which, the fixed screwdriver BROKE on the 2nd screw being removed, ebay seller sent another to replace it.

Chapter 2-32 Step 11 Page 2-88, 2-89, shows a dowel pin through the Rocker Lever Cam

I used a bright light and a 2"x3" mirror to look completely around the Rocker Lever Cam but I do not see anywhere a dowel pin could be.

The Part 8 Face Cam has an allen screw that clamps the Face Cam around the Throttle Shaft. Is this how the Throttle Shaft can be removed from the IP housing? Granted, AFTER the entire intake manifold is removed since there is not enough space for the Throttle Shaft to slide out the driver side.

If I mark the Face Cam and Throttle Shaft with a black sharpie I am hoping I can reassembly back to its original position without having to recalibrate the entire injection pump.

At least with my brother's help, we got to the point the entire IP can be removed rather easily for rebuild, worse case scenario.

Attached is a photo of the Jegg's High Creeper in place over the radiator stack. My brother is about 5 inches taller than I am, it puts him right over the DB2. I can literally lie down on my front on the platform , the DB2 ends up being just above eye level, but within easy hand reach.

 

[Mogman]

Where did you get that ladder?

 

[Crapgame]

Where did you get that ladder?

I bought mine from Jegs last fall with a 20% off coupon. It comes disassembled, mine had some faults in construction, the 4 position quadrants on the lower legs were welded on wrong, the cross way support strut was too narrow to lock into the notches. I cut the welds, pried them off with a screwdriver, then pop rivetted them in the correct position to get by until I can get it welded.

 

[Mogman]

The throttle shaft is #1 in the exploded view, it has to come all the way out on the drivers side, I am not sure that is even possible

 

[Mogman]

It looks like you do not have a 3 speed, the pictorial is of a 3 speed, it has a kickdown switch on the passenger side which has the drift pin you reference so there is no pin there.

 

[Mogman]

9.10 and 11 are not on your IP

 

[Crapgame]

9.10 and 11 are not on your IP

That drawing covers both 6.2l NA TH400 3speed and 6.5l NA & Turbo 4L80E 4 Speed. Instructions refer to inset bubble pics with specific instructions that differ between the 3 drivetrains.

I was hoping somebody here had already done this, could verify removing that removing Allen screw Part 14 from Part 8 Face Cam would allow the Throttle Shaft to be removed out the driver side of the top housing. I don't want to get in over my head than I already am. My brother is a good GM Man, knows GM high performance car stuff, not diesel. But all I am is a parts changer, and extremely limited at that.

My intent was the change out the O rings and white plastic spacer so I could get buy a few months until my brother can paint both trucks in low VOC CARC Tan 686.

The fiberglass hood was removed Redneck Style. Normally 2 healthy persons can lift it away off the hinge pins, but I'm not healthy. I had a ratchet cargo strap wrapped around an oak tree branch that I get somebody to hang a Harbor Freight 880lb 120VAC electric hoist to use to lift things I can do. Its been very helpful for HMMWV stuff as well as my rubber duck Zodiac FC530 Infantry Assault Boat/Johnson Enforcer Improved Marine Amphibious Reconnaissance System 55hp Durajet Motor, and fix tires on my lawn "tractor". Even used it to install GMV C Pillars as Turret Kit parts. I want to hang a length of steel Unistrut in my barn so I can leave the hoist suspended from the ceiling out of the weather. "Work smarter not harder" About 1/2lb to push a rocker switch up or down, that thing has paid for itself in literally saving me from pain.

 

[Mogman]

I would say yes #14 and #8 the cam is what retains the throttle shaft, but where is the procedure for calibrating that cam when you put it back together? if you have that and it does not require any special tools then you might be ok.
Just be very careful because it is possible to incorrectly install the internal governor linkage and cover and have a run away engine.
Other than that you really don't have much to lose, if it does not work out just get the IP rebuilt, I am curious if you have enough room to get the shaft out.

 

[Crapgame]

I would say yes #14 and #8 the cam is what retains the throttle shaft, but where is the procedure for calibrating that cam when you put it back together? if you have that and it does not require any special tools then you might be ok.
Just be very careful because it is possible to incorrectly install the internal governor linkage and cover and have a run away engine.
Other than that you really don't have much to lose, if it does not work out just get the IP rebuilt, I am curious if you have enough room to get the shaft out.

I'm hoping I can remove the throttle shaft out the driver side without removing the governor/guide pin, the governor on spring still moves front to rear, so engaging the notch again on re install "should" not be a problem.

I saw on BoobTube somebody altering the governor rotations to coax more HP out of the factory fuel metering:
(21) How to turn up the fuel on DB2 injection pump - YouTube

My Pop was known to hotrod cars in his younger days, even a farming tractor, but I'll consider myself fortunate if I can get it back together to the factory settings.

 

[Retiredwarhorses]

You could have the pump in and out in 5hrs…done.