PRC Solenoid Protege DX
 

PRC Solenoid always in open pos. Is that correct?
Mazda DX '98

PRC Solenoid always in open pos. Is that correct?
Mazda DX '98


That is not "correct"...if always open they would have not put the thing there. Why do you ask?

I am not sure exactly what purpose it serves controlling vacuume supply to fuel regulator.
It is powered by the main relay and grounded by the computer....I think. That is haw a '95-'96 diagram shows. Could be safty to cut pressure to fuel rail and/or part of fuel control while driving,

I will look into another manual later. It might explaine its function. But I have a 96 with 1.5

okay.
I dont know what purpose this part serves, but it looking at wiring it appears to be part of emission monitors yet is listed as fuel sytem componant. Probably both

There are 2 wires and 3 air ports (2 hoses connected and a small filter)... looking at the valve, one hose is under the electric terminals (A), one port without a hose is opposite side the electric terminals (B), and one hose out the top (C). With battery volts applied you will have ports C-B conneceted. Without power applied you will have opening C-A.

Now where is the manual to explain all the systems? The FSM I have (96 protege) does not explain very much. It is good for steps to take things apart, but not explaining the systems.

Cold engines need to run rich til warmed up. This is achieved by raising the fuel pressure til warmed up. The PCM takes a reading from the ECT and switchs that solonoid based on the ECT temp.

I think you are right...

the 1996 fsm identifies this same valve as "egr boost sensor solinoid" in emissions, and then "PRC" in fuel system. It might be same part used in two locations

I'm going to look at what's on the car.

(This is a '96 federal, and appears to be a little different than what the first guy has.)