Just wondering what the normal oil pressure should be in an 84 Z28 with the L69 motor...305 h.o.

The gauge reads 30 when it is at idle and when I rev the engine or accelerate, the gauge will go up to the 50s. This is the stock gauge by the way.

Now my car is having some idle issues...idling at 1500rpm and the gauge reads in the 50s.

 

I used to have a 305 in my 86 firebird. It ran pretty much the same pressure you are seeing so it's ok. 30psi is more than adequate at idle.

For reference, I have a big block (in another car) that idles with around 15psi - sometimes lower. No real problems there either.

My firebird now has a 350 in it, idle oil pressure is 50 psi! Honestly, I think that's too much.

 

Sounds like you have good oil pressure...I wouldn't worry about that.

Check for a vacuum leak for that high idle.

 

It is pretty hard to have too much oil pressure, pretty easy to have not enough. Either way yours sound just fine.

 

Yep, i'd never worry about too much. My oil gauge pegs out when the oil is cold, after it's warm it's 30psi at idle, and higher (pegs) once it revs up. High pressure spring too.

Vacuum leak, or perhaps the throttle is hanging up? The choke sticking on?

 

I'm not sure where the choke is at. If it is connected to the throttle linkage, then everything is in the right place....or maybe I am missing something.

There is an "L" shaped piece in front of the carb where two vacuum hoses go...I have no idea which ones though. I put the air cleaner hose onto one of the nipples, and the other is open. I plugged both of those holes with my fingers and no change in idle. No matter what I do, there's no change in idle.

Was thinking maybe it's the TPS....but I don't know.

Sometimes the car will start without giving it gas, but then it dies right away. Sometimes I have to give it gas and it'll start to die so I'll give it more gas and it'll hesitate and only go to a certain rpm...then I have to rev it a few more times to get it to rev to 5k or so. Then after that, sometimes it will idle at 1500, sometimes it'll die.

I backflushed the cooling system earlier and then took the car out for a spin. When the car was in gear, the rpm's were normal...when the clutch was pushed in, the idle went to 2000. At a stopsign or light, idle was at 2000. Put it in first gear and didn't even have to touch the gas and it went on it's own.

I was messing with the idle screw earlier, and it could be that I screwed it in all the way. But with it normal, the car doesn't stay running for long. So I'm not sure if it's a carb or TPS issue.

 

The simplest way to tell if there is too much of something in the engine is by looking at the gauge itself.

Look at the temperature gauge for example, at 260 the hash is RED. Look at the tach, it has a RED line, look at the voltage, if its too low its in RED.

Now look at your PSI guage, is there red???

I hope that answers your question on the pressure.

 

My temp gauge doesn't work....I have an aftermarket one, but I can't find where to put it on the head. I was told between spark plug 1 and 3 on the drivers side, but I don't see where to tap it.