Good day, I need some help, my VW Polo 9n BBY engine recently have been getting strange issues.

The car takes a long crank before the engine starts then my rev (tachometer) goes dead and red oil light pops out, I have checked the oil pressure and oil is fine but as soon as the issue of dead tachometer and oil light the car consumes to much fuel and the sounds like a truck.

Sometimes when I start the car it will start normally and the RPM Meter (tachometer) will be fine and no oil light, the car drives smooth and normal, but then as I drive the car will jerk/hiccups then the tachometer dies and oil light pops out. Any help....FYI I tried to hook up a OBD2 scanner but it won't connect....tried a few.

Edit: When the vehicle is fine I also noted that the Rev counter jumps up and down when on idle