Our car has always been a little slow to build oil pressure after a cold start. It would have about 5 psi. for 30 seconds then jump up to 35-40 and stay around 30 even hot. I fired it up for the Christmas parade after sitting a few weeks and it sat on 10 and didn't move. I cracked the line coming out of the pump and it had at least some pressure on it so I let it idle and after what seemed like forever it jumped up to 30 so we did the parade. Today I decided to look into it further and started at the relief valve. I took it out and cleaned it and noticed that the plunger had about 1/16" slack before it touched the spring. I took it apart and the spring seems to have a couple of coils that have lost their tension. I adjusted it until the plunger had a little pressure on the spring. I put it together and it almost instantly had 40 psi and 30 when hot. I guess I need a new spring but have no idea where to find one.