Merc63

Anyone see any issues with venting the purge valve to atmosphere??

I want to seal that input off on the blower.

Also thinking of venting the catch can to the atmosphere, should that produce any problems that anyone can think of??

bhamg

Yeah, you'll get arrested if you come down to California.

alpharabbit

What possible benefit will this have?

I am pretty sure this is illegal in all states, the odor will be unpleasant, and in many cases with BMW drivers doing this they actually lost HP and had lower trap times.

roadtalontsi

other than the fuel smell not so much.... but you'll probably need the selftest and cel's turned off for the m.e. in the tune. It uses the purge valve to pull a vacuum on the tank and shuts the purge valve. Then waits to see how long or quick it takes for the vacuum to leak out - uses an internal pressure sensor in the tank to monitor. This is how it knows when your gas cap is loose (major purge leak) or purge valve sticking/shutoff valve sticking etc (minor purge leak). Al Gore wont appreciate it either. I wonder if china or russia even know what evap emissions systems are?

He is trying to eliminate any extra complications that can cause problems. vacuum lines to the purge valve is just another source for a leak.

Mort

I think you can vent your catch can to the atmosphere if you want. I don't think it will vent the crankcase as well as the PCV System does with manifold vacuum and might cause some fuel and condensation to build up in the sump. Probably not too much of a problem if you go for longer drives and not too many short drives. Plug off the intake manifold end carefully.

My truck has a turbo and it has a valve the opens the crankcase to the atmosphere under boost and I have a one-way-valve in the PCV line from the valve cover to the intake manifold so that it does not fill the crankcase with pressure under boost conditions as the PCV Valve does not have a check valve in it and is a fixed orifice design. Lots of the truck guys running FI end up venting the sump to the atmosphere as it is an easy solution, just like in the old days, but it is not as good as the PCV system at removing fuel vapor and water vapor that evaporate from the oil when it is up to full operating temperature. Also another reason our engines are designed to run as hot as they do to evaporate water and fuel from the oil and to help clean those vapors from the sump.

roadtalontsi

hes talking about the fuel evap system Mort, not the pcv system

Merc63

ok so leave the purge valve alone.

Mort is right, I was also wondering about my catch can, if I can vent it to atmosphere instead of going back into the blower.

I want to knock off anything that could potentially let in any air past the MAFs.