socorob

I would like to hook my purge valve up on my LS1 to my original Datsun vapor canister. I know the GM PCM looked at a lot of things to determine when to open it to purge the canister. I was thinking to do it in a sort of old school way, having the valve open up at startup for a set amount of time. I would just hook up a timed relay to open up for X amount of seconds on start. My questions I've been searching around here for the last hour or so are:
1. Is the solenoid 12 volts (I'm assuming it is).
2. How many seconds should it open when the engine starts, to purge the canister?
3. Is there another way that people usually hook these up?

Thanks in advance for any help and I will still keep searching around to see if I can find anything.

79LS1FOX

iTrader: (11)

yes it is 12 volt, I use one for a fuel cell vent, its closed when the engine isn't running and it opens when the fuel pump starts, keeps from stinking up my garage with the smell of gas which makes the wife happy.

socorob

Thanks, that's what i'm trying to accomplish. I was looking at something like these:
http://www.qualitymobilevideo.com/bu...FYS4wAodvNUPxQ
https://www.delcity.net/store/Time-D...Fdi6wAodgLIB4g
Wiring it so when it gets power from start, it will start timing when the power is cut when you release the key. Think 5 seconds is enough or too long to purge the canister?

socorob

I ended up ordering this one
https://www.amazon.com/Timer-Delay-R...2NAQFRA9J69FBE

Russ K

iTrader: (1)

The GM pcm won't allow the purge valve to open until the fuel system enters closed loop.

Russ kemp

socorob

The timed relay will take the place of the PCM.

garys 68

iTrader: (1)

If you run it on startup in open loop, you'll have an unmetered air leak.
If you go with that, I would suggest using the PCV for canister vent.

socorob

Doesn't closed loop happen once the O2 sensors get hot enough? If so, I could make it wait a few minutes (5?) after startup, then open for a couple seconds. Do y'all think that would be ok to do?

garys 68

iTrader: (1)

Lots of factors into going closed loop.
But if the air inlet is after the MAF, similar to PCV, it will be metered air going into the manifold.

socorob

It will be going into the stock location behind the throttle body.

garys 68

iTrader: (1)

Canisters vented to the open atmosphere will act like an unmetered air leak with the purge valve open and the engine wont compensate in open loop. In closed loop the O2 sensor can compensate.
If you plumb the canister air inlet after the MAF and before the TB, the air flowing through the canister will be monitored by the MAF in open or closed loop, similar to PCV system.
The outlet of the canister will be plumbed to the purge valve and intake in the stock location either way.