you are going to have to get under the hood and reach behind the intake phlem and the firewall. {its a tight squeeze small hands are helpful}. when u get the pcv valve out you need a 3 or 4 inch screw to screw into the wad of screen and pull it out so u can clean it or maybe even leave it out. be careful not to lose the grommet that the pcv valve sits in.
You can find a vacuum diagram, for your 1992 Ford F1 50 pickup truck, at most Ford dealerships. You can also find the diagram at most auto-parts stores.
The smoke is because the oil is coming through air cleaner and pcv valve out of valve cover at freeway speeds blow by pushes oil through vent tube into air cleaner and PVC they are on the same line have not figured out why yet I think its a bad breather design take air cleaner off and you will oil in there
DN 50 means: "DN": Diametre nominel - Nominal diameter of the valve, and "50" is the size of the valve in [mm]. Alternative is NPS (Nominal pipe size in inches).
The 1992 Ford F1 50 pickup truck 4.9 liter engine crankshaft sensor can be found on the back of the engine. You will to remove the rear engine cover in order to access the sensor.
50
Swans Crossing - 1992 1-50 was released on: USA: 4 September 1992
Proportioning valve may be faulty.
oil is being burned threw the piston oil rings,valve gides ,sometimes its as sample as a pcv valve that is sucking to much.high mile cars will use more oil .Try thicker oil.if your using 5/30 oil.move it up to 10/30,10/30 change to 10/40,10/40 change to 20/50.
In 1992, there were the same amount of states as there are today. That number would be 50.
DN": Diametre nominel - Nominal diameter of the valve, and "50" is the size of the valve in [mm]. Alternative is NPS (Nominal pipe size in inches).
Without knowing you exact year and model it is hard to exact figures. Iridium spark plugs can run up to $20 each, PCV valves about $40, and a fuel filter can run about $50 so their prices seem about normal for a dealer. An independent shop could save you money.