There is a heater control valve on the 1999 Ford Ranger. There is no thermal vacuum valve on this year of the vehicle.
The process for shower control valve replacement involves turning off the water supply, removing the old valve, installing the new valve, and testing for leaks. It is important to follow manufacturer instructions and use the proper tools for a successful replacement.
The Idle Air Control (IAC) valve is mounted on the throttle body
It is necessary to schedule a water heater control valve replacement when the valve is malfunctioning or leaking, which can lead to issues with water temperature regulation and potential damage to the water heater. Regular maintenance checks can help identify when a replacement is needed.
I am in the process of replacing my valve for my 2000 Ford Ranger. When I pop the hood it is back and to the right and has a couple of hoses attached to it. If you buy the part it is really easy to identify it with the replacement part.
http://www.ecklerscorvette.com/corvette-hot-water-control-valve-for-cars-with-air-conditioning-1986-1987.html
On a 2002 Ford Ranger with a 2.3-liter engine, the PCV (Positive Crankcase Ventilation) valve is located on the valve cover. You can find it near the rear of the engine, typically on the driver's side. It is a small, cylindrical component that may be secured with a grommet or clamp, making it accessible for replacement or inspection.
above the rear end on the drivers side
Try your idle air control valve.
Yes, a 1993 Ford Ranger is equipped with an EGR (Exhaust Gas Recirculation) valve, as it was a common emission control component in vehicles of that era. The EGR valve helps reduce nitrogen oxide emissions by recirculating a portion of the exhaust gases back into the engine's intake. However, whether a specific Ranger has an EGR valve can depend on the engine type and specific emissions regulations for that model year.
If this happened all at once, check the vacuum lines. A cracked or broken line will cause high or rough idle.
The idle adjustment screw of the idle control valve is what needs adjusting. Either opening or closing the valve moves the throttle plate and adjusts the idle.