Need some help on retaining the canister in my 1990 Dak 360 carb swap. I need to keep the canister for both functionality and to pass my state's inspection. I reran the vent line from the tank, check. I know to run the big hose off the Carb port. The question is what to do with the purge line from the solenoid that I no longer have, as I removed the SBEC. Do I tie it straight into one of the carb ports (No vaccum at idle port for example)? Or do I need a vacuum controlled solenoid?

 

Looking at the vacuum diagram for a '86 Ramcharger (carbuerated), the purge line from the canister has an orifice device in it, then it "T's", with one line to vacuum and the other to the pcv. In older diagrams, the purge line on the canister goes directly to manifold vacuum.

But what controls the purge cycle when there's no ECM? I'm still not sure, but here's a link to AutoZone page on emissions for 67-88 Chrysler vehicles that may help:
http://www.autozone.com/repairinfo/r...00c152800529d3

 

I'm thinking the timed vacuum port along with a thermal control valve will control the purge signal. Here's a quick and dirty mockup of what I'm thinking on a carb'd engine for vacuum. Using the timed vacuum port and thermal control valve will prevent the canister from purging until the engine is warmed up and under WOT. That way, canister fumes shouldn't affect idle mixture. Thoughts on this plan? This is a conglomeration of everything I've found and specific to Dodge and an Edelbrock 1406 style carb.

 

That looks to me like it should work. I'd consider adding a small inline fuel filter in the purge line coming from the canister. While figuring out how to configure my emissions lines I ran across discussions about charcoal particles being carried through the purge line into the engine. Apparently, you can trap the migrating particles with a small inline fuel filter. Here's one of the TSB's addressing the charcoal particle problem:
http://dodgeram.info/tsb/recalls/7631.htm

 

I read the TSB....seems the issue was through the purge signal line not the purge line. I'd wish they'd call those two different things because it becomes confusing. So a small filter between the thermostatic vacuum switch and cannister but NOT on the main purge to the pcv tee.

 

Are you sure? Since it refers to checking the purge port (on the throttle body) for particles, I took it that the line that connects the throttle body to the evap is the purge line, and the one affected. In the vacuum diagrams for early magnum motors the purge solenoid (signal?) doesn't have a connection to the throttle body, just the manifold, EGR, and evap can.

It's not an area I'm knowledgeable in, and frankly I'm still not sure which line the particles are moving through. I was planning to put an inline filter on the line before the throttle body.

 

Yeah I'm pretty sure....that line is the small hose from the tbi to the solenoid which is the purge signal not the actual purge of vapors back to the engine. They say the particles clog the solenoid....no vapors go through the solenoid. They say take a small wire to clean the tbi port...that's a timing port similar to my diagram not the main vapor purge line.