11 replies to this topic

[Jimbo]

Suprise!

I broke mine. I plugged up the line coming off the manifold and pulled the plug off the solenoid. No error codes.

Question time.

Obviously it's part of the emissions system but what does that little sucker actually do? I swear i have had worse fuel economy since i broke it...

[Jimbo]

So without it, all the badness gets burnt up in the chamber, no?

[WillC]

I thought the purge control solenoid valve is as Josh said, controls the flow to the canister. And as why it is there. I thought it was an emissions control thing, it regulates and controls what fuel vapors are allowed to escape.

 

A bad or broken Purge control solenoid valve will cause engine stalls or engine sags or hesitation at acceleration.

[acres]

I believe it's the other way. Controls flow from the canister to the manifold. It "purges" the canister.
The charcoal canister absorbs fuel vapour that evaporates from the tank while the engine isn't running. It's both an emissions thing but is also supposed to prevent the smell of fuel when starting the engine.

[acres]

I find the solenoid isn't necessary. I did as jim did when I broke one and noticed no difference to anything.

[WillC]

Well, I guess the workshop manual is wrong : /

 

Here is an extract from it.

 

5. Engine stalls or engine sags or hesitates at
acceleration.

 

1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Intake air temperature and pressure sensor
4) Engine coolant temperature sensor (*2)
5) Crankshaft position sensor (*3)
6) Camshaft position sensor (*3)
7) Purge control solenoid valve
8) Fuel injection parts (*4)
9) Throttle position sensor
10) Fuel pump and fuel pump relay

[Tim.]

It opens up under when there is sufficient vacuum to purge the canister. It's not critical and can just be bypassed. I would be surprised if it made the engine stall however I can see why subaru would want you to spend your money to replace it if it breaks.

[duncanm]

It opens up under when there is sufficient vacuum to purge the canister. It's not critical and can just be bypassed. I would be surprised if it made the engine stall however I can see why subaru would want you to spend your money to replace it if it breaks.

 

wot he said.. though I guess at some point your charcoal canister may saturate and start stinking of fuel.

 

Having said that, I'm sure you can pick one up for $5 from a wrecker. There's nothing special about a B4 one.

 

Which bit did you break?  I found a 25c plastic threaded irrigation fitting was a good substitute for a nipple.

 

[Jimbo]

That's an idea!