Idle speed with a/c on

Tim Kay

Lifetime Supporter
My idle is set around 800 rpm with a/c off (webers). Whether coming down from speed or just sitting at idle the motor will die if the a/c is on. Is it as simple as turning up the idle or are there other suggestions?
Looking forward to comments /ubbthreads/images/graemlins/smirk.gif
 
If you don't want you idle set higher all the time,,,,you can just add a simple little solenoid that will raise your rpms at idle whenever you activate the a/c clutch.
You should be able to get one at anyparts store,,,or one of the aftermarket a/c specialists like vintage air.
 
Hi Tim

I would have thought 800RPM would have been enough to support a normal size compressor. I would first check the basic tune, mixtures and balance. I'm assuming multiple carb throats and in that situation balance is critical at low throttle openings including idle.

Beyond that you may need some form of idle adjustment (throttle up). On carbs the options are more limited, a cable operated thing like a choke, or maybe an electric soleniod. I Australia, Ford had a throttle up soleniod on some versions of its cars before they made the switch to the Idle Air Control Valves which are used today. You may be able to find something similar. The solendoid simply pushes the throttle open a bit and is usually located where the idle speed adjustment is. The idle adjuster normally hits it.


Regards

John
 
I think i would be checking the compressor. Can you turn the pump by hand (car off ac off)? It should turn easilyish, some resistance but doable. If not that, is it overcharged by any chance? Any noise from it? If it is enough to kill the motor, you must seriously notice a lack of power when it kicks in.
 

Tim Kay

Lifetime Supporter
I'll look into installing an electric soleniod to increase the idle after I take Eric's advise and check compressor. And yes Eric, I certainly feel the motor sapped of a bit of power each time the compressor switch is turned on /ubbthreads/images/graemlins/ooo.gif

Thanks for all the replys.

Tim
 
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