What is wrong with my oil pressure?

[jSoUhPnRA92]

Hey ppl at the forums! I have alittle problem i think. My oil pressure is at 20lb/in2 at idle or even at start and stays there during warm up. When accel. it will go up like normal but not as much as it will need to maybe to 40lb/in2. Now that is one of the problems but the thing is is that i had a motor from japan sent here and had kinda rebuilt it. New head gasket, new pistons and bored and some other things but the pressure is still the same as it was when i had the old engine in there. the oil pressure sending unit is the same one is there a possibility that it is the problem? One more thing the guy that finished up the motor didnt bypass the oil cooler but just stuck a bolt and hose in each hole like a dumb ass and it was driven like that for about maybe 2 weeks so the oil wasnt curculating but now i put an oil cooler in there and everything is run right but still the same oil pressure. Please can someone out there help me out and find out what is going on? Much Thanks!

[srzsmack]

that is strange it might be an oil pump problem, but check to see if the oil level is fine, and what oil grade are you using.