Isuzu 3KR1 Injector pump

[Rex Delay]

Anyone know the secret to remove the pump? Undid the 4 bolts and the fuel lines but unit will not lift out. Removed the kill switch plate, no further along. What is stopping the unit from lifting out and what do I do?

[skipperpete]

Hi Rex Delay
Inside the injector pump there is a fuel control rack which is connected to the governor speed control and stop mechanism by a short pin that sticks out from the rack at 90°. To lift the pump out, this pin needs to line up with a u shaped cutout in the engine casting and then it will come up enough to disconnect the pin from the governor control linkage.
If the injector pump is seized, the fuel rack rod will also be stuck so the pump removal becomes more problematic.

[Rex Delay]

Cannot lift enough to undo the linkage between the pin and what I assume to be the link to throttle. How do you unfasten the pin?

[skipperpete]

Did you manage to lift the pump out of the engine housing?try moving the stop control to move the rack pin to the cutout.

[skipperpete]

The link to the governor is held in place by a long fine spring, hook off that spring and the link plate will slide off the rack pin. The rack pin stays in the rack rod, don’t try to remove it. Try sitting the pump back on the studs and removing the link plate and spring via the hole where the cutoff lever was located. The link plate and spring stay in and connected to the governor. Why are you taking the pump off, is is seized?/ damaged?

[Rex Delay]

No fuel to #3. Assuming delivery valve on #3 pump.

[Rex Delay]

Trying to intuitively remove this is troublesome. Yesterday I ordered a full shop manual!

[Rex Delay]

Using a flashlight and a mirror, looking through the hole from the kill switch there is a long slotted plate over the pin. Do I just pry or pull it off the pin?

[skipperpete]

Originally Posted by Rex Delay

No fuel to #3. Assuming delivery valve on #3 pump.

If the problem is a delivery valve it could be extracted without removing the injector pump, just remove the lock plate and unscrew the delivery valve assembly ( carefully) ..... but if the pump plunger on #3 is stuck at the top of its stroke which is a likely scenario, you will find that the rack rod which operates the rotation of the pump plungers will be stuck tight and the removal of the link plate problematic. Is the rack mechanism stuck or free to slide fore and aft?

[Rex Delay]

Rack mechanism moves freely. Plan was to remove the pump and have it professionally rebuilt but having a hard time uncoupling it for final removal. How do you uncouple the pin?

[skipperpete]

The link should just slide off the rack pin with a bit of gentle wiggling, no pressure.

[Rex Delay]

Just tried again. Could see the linkage clearly with flashlight and mirror. It would seem impossible to uncouple while inside the housing, it must lift clear first. Lifting clear is the problem as I am coming up against something solid. The pump will not lift clear of the stud on the foreward outboard corner. What am I missing? Have seen drawings of shims and gasket, they both have notches for the pin - it should lift out easily.

[skipperpete]

Maybe try removing that stud, or all the studs? Here’s a picture of the entire governor , hope it helps

[Rex Delay]

Thank you. That picture is great! Where did you get it? Got my shop manual this afternoon and it confirmed what I was thinking and you mentioned - remove the stud. Preliminary, non destructive try did not work. Will talk to local Isuzu guy in morning before destroying the stud.

[skipperpete]

Google "Diesel engine basics" website, it asks you for a name and email address and sends you an email with the selected engine manual link.