David L. Lutz

What is the purpose of this Vacuum diaphragm valve in the charcoal system?

(I notice when testing the diaphragm, that the air passage is closed without vacuum. Therefore, when the engine is running it will be open and when the engine if off it will be closed.)

Its # 7 in the pic.

ZEUS+

The charcoal cannister stores vapors from the fuel tank and purges them through the engine when running. The valve also prevents the charcoal from being sucked in.

David L. Lutz

Speaking of charcoal, my lines from the cannister all the way back to the solenoid valve are full of little round log bits of charcoal. Is this normal?

ZEUS+

No, cannister has failed and valve ruptured.

David L. Lutz

I have new valves (both the solenoid and vacuum) do I need a new cannister or can it be refilled or ?

ZEUS+

The cannister and diaphragm valve should be replaced.

David L. Lutz

Roger,
Are you reading this?

David L. Lutz

Has anyone else had to replace the cannister?

Rob Edwards

I actually bought a replacement canister when I went into the wheel well to replace the Y-connector (not outrageous at $40), but was advised that replacement was not necessary, so it's still on the shelf. For all the hundreds of posts I've read about people changing the Y-connector, I can't recall hearing anyone that changed the canister.

Could a fresh one possibly have any measurable effect on tailpipe emissions, or is it purely to cut down on evaporative emissions?

David L. Lutz

This pic. show the charcoal that came out of the valve. Actually this was only about 1/3 of the total amount I got out of all the lines!

ROG100

Never sold one before so they are not replaced very often.
$60 new. 993 201 221 01

Jim bailey - 928 International

David do you have mice in your part of the country ??

David L. Lutz

You would think. I have removed about a liter or so of this crap!

If you will remember when I ordered the Diaphragm valve I thought it was just dry rotted and the diaphragm had crumbled, but when I checked closer, and then removed the lines they actually were full of the charcoal.

Tomorrow I will pull the cannister and check it out further.

StratfordShark

I must have been lucky. Replaced the vac valve when I found it wasn't holding vacuum (had taken off the hose when I was removing intake so seemed a good time to check it) and got round to replacing Y-connector a couple of days ago.

The hoses were clear so the valve can't have failed in same way and sucked up charcoal.

I was wondering if it was beneficial to replace old canister so reassuring to hear it's not necessary, though I wonder if at some point the charcoal becomes saturated/ineffective?