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View Full Version : A/C idle increase with weber carb?



greenteagod
03-22-2013, 12:49 PM
Has anyone with a weber carb figured out how to properly hook up the little vacuum switch for when the air conditioner is running. I'd like to not have to have my idle set high just to compensate for the AC running if possible, but so far I haven't figured out exactly how to run the vacuum lines to make the switch properly compensate.

camoit
03-22-2013, 04:26 PM
There should be a switch on the firewall with 2 lines on it. But how to make it work is another thing. You will need some kind of actuator and a way to adjust make it adjustable. Then have it hook to the carb. and pull the throttle just slightly. OR you might be able to have it make a vacuum leek and it will rise the idle on that alone.
Or instead of pulling the cable it can be a stop of some kind.

greenteagod
03-22-2013, 04:28 PM
Yeah the switch itself works. When I turn on the AC it allows vacuum to pass through it, otherwise it closes it off. Might just have to go the way of a leak on it though to get it to bump it enough because otherwise it doesn't seem to do much.

greenteagod
03-22-2013, 05:05 PM
Hmm, well did a little rigging up, and it definitely puts a strong vacuum through this white valve on the firewall if I have the AC on. But man it did not like that. As soon as it tried running all that Vacuum through the charcoal canister it bogged from about 750 rpm down to 400. Do those canisters clog up?

pennyman1
03-22-2013, 06:59 PM
yes they can, but that sounds more like it created a massive vacuum leak than it being clogged. On the original mikuni, there was an electric solenoid added to push the throttle arm open when the A/C clutch engaged, at least there was on Geronimo before I put the weber on. Never got around to getting that solenoid to work on the weber.

greenteagod
03-22-2013, 09:11 PM
Ah, I see what you're saying about the solenoid. About the vacuum leak though, I'm not certain how the internals of the canister work, but that white valve, it is pulling a decently strong vacuum through it, but if I don't have it connected to the line going to the can, no problem at all. Once I plug it in to the can, that's when it bogs down. But really, those vacuum lines I hooked up there are probably not the right ones at all considering the solenoid. I just figured it did the rev increase through creating an air leak. More to it than that though =)

camoit
03-22-2013, 10:47 PM
On my truck there was a solenoid on the firewall that had manifold vacuum to it. Then the other end went to the carb where it had a 'dash pot" and that would pull a little thing to make the engine speed up.