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Old 07-28-2009, 06:07 AM
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FSK1460 FSK1460 is offline
Join Date: Aug 20, 2004
Location: Tulsa, OK
Posts: 164
Well after playing around with this new charcoal canister, I think I figured out how it works. The CP1010 model basically has a built-in bowl vent solenoid switch, which explains why the "bowl vent" port is triggered by the purge sig. (Sorry still don't have pics yet).

On our engines, the bowl vent solenoid is closed when the engine is running, and open when its off so as to allow fuel vapors from the carb to enter into the canister.

On the CP1010 canister, the bowl vent port is open when the engine is off, or not warmed up. Once the engine temp hits 125F, the Dual CTO switch opens and allows vacuum to the purge sig port on the canister. This internally shuts off the vacuum for the bowl vent port. With this model canister, you can eliminate your bowl vent solenoid, which on most of these vechicles is already broken.

The tradeoff is, and I'm not sure if its an issue or not, is the purge port has full vacuum applied all the time. Whereas on the original canister, its "metered" by the ported vacuum signal. The more engine RPM's the higher vacuum going thru the "purge signal port" which in turn regulates the vacuum flow of the purge port. I've attached the vac diagram and colored in the lines for the canister (original one). Although with MicroSoft Paint utility, I'm not sure if the notes at the bottom are readable.

Since I have an Edel 1406 which doesn't have the bowl vent on the carb, I'm thinking I could have gotten by with a three port canister. What I did on this one, was to remove the hose from the vapor separator going to the bowl vent, and capping it off at the separator. And left the second port on the vapor separator still tied into the PCV line. Incidently, the vacuum going thru the separator only draws 4 inches of vacuum while the other line from the PVC draws 19 inches.

Since my purge line is no longer metered, I probably could have left the bowl vent line and the purge signal line off. Hope this makes sense. I'll post some pics when I get my camera going.
1990 GW: Borla Turbo XL muffler, MSD 6A, Blaster Coil
Rebuilt 360 with RV cam. Edelbrock 1406 and Performer Intake
TH727, NP229, 3.73's with 31' BFG's. BJ's 4" lift with Rancho 9000's
BJ's Aluminum radiator
Black with Burgandy interior.
Tulsa, OK
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