please help me!! no oil pressure in new pump

[1970/240z]

hi guys, i just rebuilt my L28 engine and i replace the oil pump for a new one. i stated the car for 20 sec and then turn it off. then i notice there was no oil pressure because i check the oil filter and it was empty and also my gauge marked 0 pressure.. i don't was to stated again because i am scare i can mess it up.

 

please help me . should i buy a another pump, a used one? or what can it be,

[Chemicalblue]

You should always fill the pump with oil before installing it. You can also try pulling the plugs out and the injector clips off and turn the motor over with the ignition until you see oil pressure or open the fill cap and see oil on (squirting out of) the cam. Hope this helps

[HowlerMonkey]

There is a secret squirrel technique to backfeed the pump.

 

I used the clear plastic tubing that comes with those lame hand pumps designed to pump from anti freeze containers.

 

I used a plastic tube connector to fit it to a funnel.

 

Then I remove the oil filter and stuff the clear tubing into the oil gallery that feed the filter (not the one in the center) by stuffing it in pointing toward the front of the car as much as possible. I got it in about 1/2 an inch by squeezing and prodding it.

 

Then you put a bit of oil in the funnel and crank the engine by hand backwards.

 

You should see the oil going down the clear tube if you leave a bit or air bubble to use as an indicator of flow.

 

If you crank half a quart or more and fill the filter, you should get pressure right away but I took out the oil pressure sender and watched while cranking with a remote starter switch until I saw oil coming out and quickly put the sender back in before firing the up the engine.

 

I actually had to do this twice since I did it once and got zero pressure.

 

If that happens then you have a bad pump or a pickup that is sucking air.

 

I replacedthe pump with another I had lying around and repeated the process and got pressure right away.