Idle issues

[sdb2515]

Hey there. New to the forum and first posting. I have a 78 c10 350/350 with a Q-Jet, which I recently purchased. It is a nice California rust-free truck. I decided to throw on a set of chrome valve covers since the original steel ones were leaking. In doing so, I eliminated some of the vacuum to charcoal canister lines that filtered back into the carb. These vaccuum lines had been teed into the vacuum coming off the pcv valve and went into the carb bowl outlet. I capped off the outlets on the charcoal canister, and now run without a tee from the breather (there is no pcv) to the bowl.

I have checked for vacuum leaks (with carb clean spray), and didn't find any. Neverthless, the truck doesn't idle as well, and I am curious if it had anything to do with the elimination of the feeds from the charcoal canister.

I also plan on adjusting the carb. The manual says to lean it out completely (until mixture screws bottom out) and then loosen 4 turns. In past experience with Q-Jets, I had always just leaned it out until it began to stumble and then backed it off half a turn.

I appreciate any advise. Thanks.

[grinch4om]

you need a pvc and the vent pipe on the top part of the carb is for venting vaoprs to canister. If you plug this hose you might be experiencing pressure differencial in the float bowl hampering fuel delivery, open the pipe and see and instal a pcv valve on one side of the valve cover and a vent on the other