Chevrolet Repair: Will turning injector pump on 6.2 diesel give me more instant response?, check valve, fuel filter

Question
1987 GMC with a 6.2 diesel non turbo.    If I turn the injection pump one way or the can I get more instant response?It seems a little sluggish on takeoff.  

Answer
Hello Randy,
If you advance it by turning the pump, it might run better, but that is only if there is wear internally, and you compensate for that. It is easy to advance it too far. It can't take much before it runs worse, but you can try it.

Make sure the fuel filter is clean, the transfer pump isn't sucking air, and the check valve in the return line from the pump isn't plugged with something.
That valve is screwed into the top of the injector pump, pointing straight at you when you are in front of the truck looking at the engine.
There is a little clear plastic check ball and spring in there, and I have had them get plugged and stuck by pieces of rubber.
There is a little needle operated by a solenoid inside the injector pump that pokes up inside the valve and pushes that little ball to open it. With the valve in your hand, you can work the ball with a tiny nail or paper clip if it isn't stuck.


Van