Oil pump problems

Unknown

I am having the devil's time fixing the problem with my oil pump. I've

done everything I can think of to repair it, but still no oil pressure.

Here's what I've done:



1. Disassemble the pump to make sure nothing sticks, reassemble. Spring

is fine. (I'm not positive it's the "right" spring -- this extends about

2 inches past the back of the pump itself when in a fully uncompressed

position, though it does compress enough to allow the plunger to go all

the way into the pump body.)

2. Replace piston with one from a partial spare pump -- the original

piston had a depression worn into it where the eccentric wheel had been

rubbing on it. (Is that normal?)

3. Check oil line to oil pan to make sure it's not blocked (blow air

through it and hear bubbles, then draw oil through it using a length of

rubber hose as an extension so I wouldn't get a mouthful of oil.

4. Check line to pressure gauge to make sure it's clear. (When I blow

hard on the line, I get about 1.25 lb reading on the gauge, so I know it

works.)

5. Check the eccentric drive wheel to make sure it is rotating (it is).

6. Remove the plug from the front and check to see if the piston/plunger

is moving (it is).

7. Prime pump with oil poured in top.



It still won't work.



What am I missing here?



Of some possible value in diagnosis, the pump was non-functioning when I

got the car running. I disassembled it and got it going with about 3.5

PSI. After a while, it begin to behave erratically. Just before it quit

entirely, the oil pressure was zero, then went up very high, (full

scale), but bouncing up and down very rapidly. This lasted for about a

minute, and then the pressure went to zero and stayed there.



Any guidance anyone can provide for additional things to check would be

appreciated.



Separate issue: the amp gauge reads "backward" -- when the engine is

running and generator working, it shows "discharge". When the ignition

is on but engine not running, it shows "charge." I have checked the

wiring, and the terminals are NOT reversed from what is specified in the

wiring instructions. I guess this is harmless...but would it hurt

anything to just reverse the connectors so that it reads "right"?