I had a pump issue once, I bought a pump at a wrecking yard for 100.00 and it was worse than mine. So I took my pump apart, and cleaned it the vanes were polished with 1000 grit paper and I replaced all the o-rings. I used the tard pump as a guide to get mine apart, and well the security screws with the Tri-angle was a bother but I filed a screwdriver to fit and it worked, only having a Haynes was a guide. I put it back on the car and Cracked the stand off unions on the manifold and all the lines and Cranked the engine after getting spray all over and tightening them the engine started.
I took the pump loose and moved it a bit both ways until I got it running well and locked it down. It got me about 45 mpg. not bad for a pump with 200+K on it. Later on I bought the dial gauge and I was at about 95 on it. So you can tune it by ear if you must. I had the pump on and off so much that I suppose I was lucky in getting it back together. You might want to take the old pump to a Diesel Pump rebuilder that is local to you the kit is only like 60 bucks.