What oil do i use for a 1978 vw dule injection

I own a Beetle 2.0 year 2000 and it stalls after around 45 minutes of starting it. I have already changed its coil, camshaft and crankshaft sensor, fuel pump, relay 409 and throttle body but it keeps turning off suddenly. I've been trying to find a solution for a month and a half but without positive results. Does anyone know something about it?

2 L inline 4 2000 year. No fuel pressure unless you block the fuel return line. And a random misfire on at first piston 4 now on piston 1? the coil pack was replaced with new, new sparkplug wires, new temperature sensor, replaced the fuel pressure regulator. Problem persists... low to no power on acceleration can move car when rpms are slowly raized but only up to 3000 rpm. If you block the fuel return line can accelerate but the fuel pressure will remain at 80 psi, standing fuel pressure is at 38 psi; when vaccuum line to fuel pressure regulator removed the standing pressure goes to 48 psi.
No hair left on head because of scratching...

my beetle has an oil leak,

This little bug has definitely been a blessing and a curse. I've done some work and changed out some parts already. I've changed out the five coil packs, spark plugs, and physically removed all the fuel injectors and clean them out with carburetor cleaner. After putting everything back together, I still get a check engine light with multiple cylinder misfires. Unfortunately while doing this maintenance, I broke a few of the wire connectors that connect to the coil packs and the wire connectors that connect to the fuel injectors. The plastic has become very brittle and just simply disintegrates… Vollständig lesen

Check engine light is on when I come to red light the motor revs up and down I checked spark plugs they are all good. Some kind of vacuumed leak is happening. And seems to be oil leakage on bottom of engine

My stepson "changed" my "oil" but it was the transmission fluid he drained and now it has been running with no fluid what is the fix on this.