Are the lines from the TB to the Purge canister really necessary?

[itoktoeatfish]

Simon, you said in the linked post that your car, or van as the case maybe , ran leaner with out it. Hows does that happen when its only sucking fumes just above idle, anything past that you should be building boost and closing the check valve?

[turbovanman]

Quote:

Originally Posted by itoktoeatfish Simon, you said in the linked post that your car, or van as the case maybe , ran leaner with out it. Hows does that happen when its only sucking fumes just above idle, anything past that you should be building boost and closing the check valve?

When your cruising, your in vacuum so yes, your pulling vapours out of the cannister. I can't explain it, I was going to Portland and had just got my egt guage. I noted my temp for a while then pulled over, disconnected and plugged the purge lines and started driving, went up aprox 500 deg from before at exactly the same speed!