I agree with haro. I usually see about 40 in my '93 at idle :?

Remember that oil viscosity (thickness) affects oil pressure. Oil viscosity is affected greatly by temperature.

If you have a leaking injector, gasoline will dilute the oil and that will also lower the viscosity and therefore the pressure.

Running heavier oils will increase the oil pressure. If you are currently running 5W-30, change to 15W-40 and see what I mean.

Assuming your cooling system is in good shape, running a 180 drilled thermostat will keep the engine and the oil cooler and the pressure higher. The engine temperature dropped and oil pressure increased in my '95 when I installed a transmission cooler. That'* because the engine coolant no longer had as much transmission heat to absorb with a separate cooler for the trans installed.

Don't get too excited until you have tried a few things and installed a mechanical gauge to see what pressure you really have.

Diluted oil will lower the pressure across the range. But, even with diluted oil, the pressure will increase with engine (oil pump) speed.

I had around 30psi on my gauge when I got the car, but did an oil change 1,000 miles early and used a Motor Flush kit for the engine oil. The oil came out pretty black! But after the oil change the gauge stays at or above 40.

Many people don't like oil cleaners that remove sludge because small oil holes can be clogged by sludge.(so, I have been told) I on the other hand motor flush every 3-4 oil changes. My Ford Explorer is still running at 280,000 miles and my 390 didn't have varnish/sludge anywhere when we opened it up to do some head work. I'm kinda big about cleaning solvents like motor flush and fuel injection cleaners. Tranny fluid works well too.(but that'* another story)

If your cool with it you could do a "motor flush" on the engine oil and see if it helps any.