De-Smog Help (1 Viewer)

[HitTheDirt]

Normally you'd pull vacuum for the AC idle up to the smaller fitting on the back side of the intake manifold (adjacent to the brake booster vacuum port) instead of the gas filter/front side of intake manifold, but the setup pictured is essentially identical in terms of functionality.

Ah that's right, you mentioned that before. Will switch that tonight

 

[HitTheDirt]

The large hose you mention is the other EVAP hose that runs to the carburetor. It looks correct but I've got a Trollhole carb and can't cross reference my own engine to be sure.

OK thanks, was wondering what that was and where it went. So the other drivers side evap hose further outboard is a vac line then?

 

[HitTheDirt]

Ok new issue, it appears my truck only came with one 4 point VCV. Can I use just one and rout the original purge line to the carb insulator base? It's the u shaped hose in the pic, coming off the firewall from the vent control valve on the charcoal canister. My canister has an electrical control on the vent control valve. Do I still need vacuum from the BVSV then??

Then I can just use one VCV for the distributor circuit?

 

[HitTheDirt]

Ok I am an idiot. I found my "missing" VCV on the underside of my air cleaner. Progress continues..

 

[peterabbitcook]

OK thanks, was wondering what that was and where it went. So the other drivers side evap hose further outboard is a vac line then?

Have a close look at the emissions manual.
One of the carb evap hoses is for fuel vapor to get adsorbed into the canister when the ignition is switched off - the VCV for this circuit fails open (switch power closes the valve). Make sure you hear it clicking when you switch the ignition on/off. This VCV sits near your canister, fat hoses go to the firewall and canister.
The other carb evap hose is for fuel vapor to get pulled from the canister and burned when the vehicle is warmed up and in motion. The VCV for this circuit is actuated through a BVSV so that it only pulls vapor when the engine is warmed up and the throttle plate is above the advancer port. IF I remember correctly this VCV sits on/near the driver side of the hood - fat hoses go to the firewall and base of the carb, 1 skinny vacuum line to BVSV 1, 1 skinny vacuum line to air cleaner.

Chase the hard lines on the firewall back to the canister and make sure their hoses are connected in the right positions.

 

[HitTheDirt]

She's alive!! Thanks for all the help!

 

[UGA2018]

Enjoy her!! Nice work!

 

[HitTheDirt]

Oops somehow I disconnected the carb fan. Time to investigate!

 

[HitTheDirt]

SO now that it's getting cold out I find that it is starting hard, well it will fire up after a few cranks but want to die unless I give it a bunch of gas to keep the rpm's up. I end up around half choke to get it to idle after revving for 20 seconds or so. Then there is some hesitation/bogging while driving until it's warm and then it's running like a champ. Any quick ideas on this? Maybe I bought the wrong BVSV? I bought a new purple one. Distributor advance?

 

[OSS]

Check the vacuum. Those are classic symptoms of a vacuum leak. Too lean of mixture for cold engine.

 

[ibis1969]

Hi HitTheDirt-
Can you tell a difference with the de-smog, header, JimC carb, etc. setup? How much better does she run now?