Lower RPMs and power fluctuation when AC is engaged
10-26-2013, 12:18 PM
#1
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Car: 1982 Z28 Camaro
Engine: 5.7 L 350 V8
Transmission: Manual
Lower RPMs and power fluctuation when AC is engaged
I have an 82 Z28 with a 350 V8 carbureted. When I first purchased the camaro, the car would not idle unless the ac was turned on. If the ac was off when it was idling, the RPMs would slowly increase to about 1500 then it would stall out completely and shut off. It seemed like the running of the AC was the only thing that lowered the RPMs enough to keep it from idling too high.
After a while, I decided to take it to my mechanic and he adjusted the carb so that it idled lower and I wouldn't need the AC on to regulate it. Well now my problem is the opposite..
Now whenever I run the AC, the RPMs lower significantly which I turn, dims the headlight brightness, and dims every light and power operated device in the car. Using the AC does not cause the car to turn off but it causes everything to malfunction including the radio. If you give it some gas while it's idling. The lights and everything else brightens as long as you're giving it gas. What could this be?
After a while, I decided to take it to my mechanic and he adjusted the carb so that it idled lower and I wouldn't need the AC on to regulate it. Well now my problem is the opposite..
Now whenever I run the AC, the RPMs lower significantly which I turn, dims the headlight brightness, and dims every light and power operated device in the car. Using the AC does not cause the car to turn off but it causes everything to malfunction including the radio. If you give it some gas while it's idling. The lights and everything else brightens as long as you're giving it gas. What could this be?
10-28-2013, 04:51 PM
#2
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Car: LOWERED ♦ CRIMSON METALFLAKE
Engine: ► 400 KUBES ◄
Transmission: 765R4
Axle/Gears: EATON POSI 4.56
Idle Chatter
The alternator is slowing down to the point of turn-off.
When the AC is turned on, a throttle stop is supposed to be engaged to open the throttle a little, to return the idle back to normal.
Sounds like yours is not.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Spin Me This Week . . . I’ll Spin You Next Week
When the AC is turned on, a throttle stop is supposed to be engaged to open the throttle a little, to return the idle back to normal.
Sounds like yours is not.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Spin Me This Week . . . I’ll Spin You Next Week
10-29-2013, 07:56 PM
#3
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Car: 1982 Z28 Camaro
Engine: 5.7 L 350 V8
Transmission: Manual
Re: Idle Chatter
The alternator is slowing down to the point of turn-off.
When the AC is turned on, a throttle stop is supposed to be engaged to open the throttle a little, to return the idle back to normal.
Sounds like yours is not.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Spin Me This Week . . . I’ll Spin You Next Week
When the AC is turned on, a throttle stop is supposed to be engaged to open the throttle a little, to return the idle back to normal.
Sounds like yours is not.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Spin Me This Week . . . I’ll Spin You Next Week
10-30-2013, 06:39 PM
#4
Re: Idle Chatter
To rule out the alternator, take it to your local parts store and have it tested, but I'm pretty sure this wouldn't be caused by your alternator.
11-04-2013, 04:56 PM
#5
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Car: LOWERED ♦ CRIMSON METALFLAKE
Engine: ► 400 KUBES ◄
Transmission: 765R4
Axle/Gears: EATON POSI 4.56
Idle Chatter
Yes you should get the Idle Stop Solenoid checked to make sure it’s energized whenever the AC compressor is running.
It sometimes simply needs adjustment, therefore you won’t have to buy a new one or pay for electrical diagnosis.
Also you can check it yourself.
The Idle Stop looks like a can with a rubber boot and a screw-head or nut at the end.
It’s located at the carburetor left, and has a wire going to it.
With the engine idling and the AC off, observe the distance of the screw-head or nut’s protrusion.
Then turn on the AC and re-observe.
Does the screw-head or nut protrude more with the AC on?
On less maintained cars it’s sometimes necessary to blip the throttle after turning on the AC to allow the Idle Stop to extend.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
I Never Fight In The Pits . . . . . . . . . My Pit Crew Does That For Me
It sometimes simply needs adjustment, therefore you won’t have to buy a new one or pay for electrical diagnosis.
Also you can check it yourself.
The Idle Stop looks like a can with a rubber boot and a screw-head or nut at the end.
It’s located at the carburetor left, and has a wire going to it.
With the engine idling and the AC off, observe the distance of the screw-head or nut’s protrusion.
Then turn on the AC and re-observe.
Does the screw-head or nut protrude more with the AC on?
On less maintained cars it’s sometimes necessary to blip the throttle after turning on the AC to allow the Idle Stop to extend.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
I Never Fight In The Pits . . . . . . . . . My Pit Crew Does That For Me
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