walkerhoundvm's rebuild thread

AJ2393

Scrambled in the Head
LIFETIME
CJ-8.com Member
City
Westport
State
MA
Good question. The check valves are built in to the 20g tank, so they're still there. In the OEM CJ setup, the canister is purged to the carb by a signal provided by a mix of temperature change (through the CTO valve) and manifold pressure which opens a simple valve in the canister. The default state of the canister is closed, and scavenging only happens with the vacuum signal.

With the LS, it's a signal from the computer to a solenoid valve at the front of the engine. There's a canister, but it's a simple flow-through canister and scavenging happens with the PCM signal to the external solenoid valve.

When I was redoing the LS harness, I was following a guide without thinking for myself. The guide essentially deleted everything outside of what it takes to turn on, off, and a few essential sensors. The canister purge valve was deleted. I figured this out too late, it was going to be a major undertaking to add a single wire back to the harness for that valve. On top of that, I'd have to find some place to put the Chevy canister, which is roughly the size and shape of half a cinder block.

Decided to deal with it "in the future." For now it vents to the CJ OEM canister without being purged. So far, no gas smell accumulating in the garage, but I'm sure it's probably costing me 0.1mpg ;)
Thank you for the education on this, especially with the LS swap. Trying to stuff something modern in something 40 years old looks like it has some real complicated challenges. It's like adding gremlins on top of the gremlins that these Jeeps already had leaving the factory. Also I had no clue the Chevy evap canister was so large. I have no idea where you could bolt that up something that big in an already crowded engine bay, maybe where the factory tire jack was mounted on the passengers side fender? Awesome and educational build nonetheless. Did I mention I am totally jealous of your Jeep? It must be the copper brown paint, I seem to have a thing for that color.
 

walkerhoundvm

Just trying to stay upright
LIFETIME
CJ-8.com Member
City
Cave Creek
State
AZ
I have no idea where you could bolt that up something that big in an already crowded engine bay, maybe where the factory tire jack was mounted on the passengers side fender?
I think there'd be a good spot back under the bed somewhere, just have a long line back up to the engine.

Did I mention I am totally jealous of your Jeep?
As I was of yours way back when :) After seeing yours, I was more than happy to find my OEM color was CBM and waited a long time to get it back to that color.
 

AJ2393

Scrambled in the Head
LIFETIME
CJ-8.com Member
City
Westport
State
MA
Your Jeeps come a long long long way. Based on this thread it been at least 10 years, and if my math is correct you lived in three different states during that time. That means you've shipped it at least twice, when it was just a collection of parts and a dream. I salute your perseverance, and so happy for you that it turned out so nice. Maybe someday I will get back in the saddle and find my "next" one, but nothing will be as nice as the CBM one. I messed up big time selling it. Something I will regret for some time.
 
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