I was just trouble shooting a rich fuel condition and ended up doing a vacuum test on the EVAP solenoid.

When I put my vacuum tester on the side which goes to the engine it doesn’t hold any vacuum. Am I right in saying the solenoid is bad?

I do get the rare p0445 and p0455.

 

Hi cdc,

I can't recall the year, model and engine of your Jag, but in most Jags I believe the carbon canister Purge Valve is normally closed. It receives a constant ignition-switched power supply and the ECM connects it to ground to pulse it open, similar to the manner in which fuel injectors are pulsed open. If your Jag has a Canister Close Valve, it may be normally open, but I'm not sure. Do you know which valve you were testing?

Cheers,

Don

 

It was the one under the hood behind the throttle body. It has a vacuum from the engine then 2 lines on the other side. It has what looks like a spinning cap on the top. I can get a pic or part number if needed. When I looked at a generic Youtube video they say it should hold vacuum and release it when the solenoid is activated, mine never holds any vacuum.

 

Year, model and engine of your Jag?

 

2000 Jaguar XJR

 

Here are the components from the parts diagram at jaguarclassicparts.com:





I'm fairly certain that the purge valve should be normally closed, but I'm not certain about the canister close valve. It may be normally open. I haven't tested one on an X308.

To give your purge valve a more thorough test, you might try powering it with a 9V battery to see if its state changes to closed.

Cheers,

Don

 

Ok I’ll give that a try.

Thank you

 

You can test it with straight 12 volt power and apply vacuum. Should hold

 

The EVAP solenoid valve on my 1999 supercharged engine (the one that has has a spinning cap on the top) does not have a port on one side and a port (or two ports) on the other side. There only two ports positioned at one side and are parallel and fairly close to each other. One port has a slightly larger diameter than the other. When the solenoid valve is disconnected from power, both ports hold vacuum but if I blow through the larger port, the air goes through with a small resistance and I feel the opening of some kind of check-valve.

 

You people are confusing EVAP valve and PURGE valve.

bob