Finally got the 84 running. just needed some more tweaking on the choke and throttle. Now when it warms up and i let it idle for a minute or two i start losing oil pressure. When I first start it up i get 50-60 psi, after it is running for a minute it slowly starts losing pressure. If you rev it a little i get pressure back, but if you let it run for two long the pressure starts dropping to 0, weather you give it more gas or not. I am at a loss. I have looked through book and only thing i can think of is a bad sending unit, I hope, But i dont know. Is there any way to check for oil pressure without a guage, or any signs to tell me if the oil pump is dead?

 

You sure there is enough oil in there? Seems like it might not be the oil pump since you do get pressure at startup. I'll assume you changed the oil and filter already?

 

Your on the right track with the sending unit being the culprit. These are notorious for failing and will give a false indication of low pressure. Just by the way you described it point to sending unit. You can try cleaning the connection but more often than not it will need to be replaced. For peace of mind connect a external oil pressure gauge to comfirm a faulty unit.

 

Cold oil is thicker and shows as a higher pressure. Viscocity makes a diference too. 20W50 will read higher on cold start than 10W30. If you're showing oil pressure within factory specs by the time the engine has warmed, then it drops off, pressure is good, sender or gauge isn't.

When's the last time you checked/changed your oil? If the oil is old and it's getting contaminated with fuel, pressure will be even lower.

 

oil and filter have been changed already i am going to go swap the sender here in a minute. I used 20w50 in it.