Testing the EVAP system
I am trying to help a retired Gent. with a problem on his Mazda B4000 (Mazda/Ford Ranger) hahaha
He has thrown the code P1443;
I have replaced all of the hoses between the intake and the metal tube mounted on the frame below the power brake booster that goes back to the fuel tank, and I replaced the Vapor Canister Purge Solenoid. It still came back with P1443. I have visually checked the lines all of the way back to where they disappear over the fuel tank with no problems that I can see.I removed the Purge Flow Sensor or Thermistor and could not blow through it untill I put 12 volts into it and it opened right up. The carbon canister has been removed and I could see no cracks or voids in it. Now my questions:
1. If you hold one finger over one of the hose connections and blow into it, should the air be able to escape through the vent openings at the top? How about if you hold your finger over the other one and blow the other way?
It seems like if this is supposed to be a sealed system that there would be no way for fumes (or in this case air) to escape from the system.
2. What should the results be if I remove the hose coming from the carbon canister and placed a vacuum gauge on the fitting leading out to the fuel tank, and then started the engine? Shoud I have a constant vacuum show up on this gauge?
3. Is there any other way to test the Purge Flow Sensor (Thermistor)?
4. What else can I do before I have to drop the fuel tank to check everything up there?
Thank you guys! I know there is someone out there that can suggest something!