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Topic: Runs poor with A/C on (Read 1404 times) previous topic - next topic

Runs poor with A/C on

Hi everybody - I've got an 84 T-bird with a 5.0 (CFI).  The car runs really good and idles smooth except when the Air Conditioner is on.  When I turn the A/C on - it hesitates upon acceleration and nearly cuts off upon deceleration.  Does anyone have any ideas how to troubleshoot?

Thanks!!

Re: Runs poor with A/C on

Reply #1
sounds like the idle is too low? I have had that happen on a 4 cylinder, But I have never had it happen on a v-8, so I am not sure. Is it only when starting out, or when you are reving it up?
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

Re: Runs poor with A/C on

Reply #2
Hi,
Thanks for the reply.  When the A/C is on, the car hesitates whenever I accelerate quickly (either from a stop or in motion).  It is not really noticable on gradual accelerations.  This might sound crazy, but it seems to worse when it is exceptionally humid outside.

Re: Runs poor with A/C on

Reply #3
Sounds like possibly the idle speed motor is not increasing the idle when the A/C is on. Have you watched it to see if it is operating the throttle??? It should move when switching the ign on, and when the A/c is turned on..

Re: Runs poor with A/C on

Reply #4
i have a 86 cougar with the v-6 and i had a similar problem..i fixed it by changing the vacuum line connection box thats attached to the a/c heater slide control panel. got one at a junk yard..my a/c stays humming all the time...idle or accelaration. the only problem ihad replacing it was they don't give enough slack in the connection wires to pull the unit from the dash. just be careful. hope this helps

Re: Runs poor with A/C on

Reply #5
no sooner did i post you a reply and my a/c is acting up again...comes out the vents then stops and comes out behind dash. i'm checking it now