MUSTANG BUCKS WHEN A/C IS ON WHILE DRIVING ??

[rispoli_23]

hey guys hope u can help this week i have used my a/c for the first time since last year and i noticed while im driving and the a/c is on my car surges like its missing or loosing power even when the cruise is on its like it goes and then looses power and then goes again its crazy and its never done that before any suggestions will be much appreciated thanks in advance

 

[N8Dogg98]

Mine does the same thing, but also does it if I try crusing at 1500 RPM's. It's probably a result of your cams.

 

[rispoli_23]

yeah i was wondering about that but it just dont seem that it did it before or i just didnt notice it

 

[N8Dogg98]

I'll wait for others to chime in. Perhaps this is a tuning issue (for both you and I) and it can be corrected by datalogging while strapped to a dyno at low rpm's and low load. If anyone has experience with this and it was fixed after an additional tuning session I'd be interested to know the details. Then I would consider going back to my tuner and having another dyno session to tackle some of these driveability issues.

 

[nyuk98gt]

N8Dogg98:

Just datalogging normal driving - especially capturing a bucking event - should be enough for your tuner to see the problem. There's a small table for isc_air_adder_for_AC (or some similar name) and an RPM adder when the AC is on. These might need to be bumped up. EGR can make your car buck at lower RPM's or when 'lugging'. Again, datalogging should help your tuner sort it out.

rispoli_23:

The AC compressor is putting more load on the engine so that is why it feels like the power is coming and going. The compressor cycles on (power feels like it sags) and off (power comes back). The hot summer air (not as dense as the air is in fall or winter) saps power, too, and makes the engine feel weaker than normal.

Chris

 

[rispoli_23]

thank you and i have always noticed a difference in power when the compressor would click on and off but now it feels like it cycles on and of much more like ever 30 secounds to a min i can feel it loose and gain power is there anything that would cause the a/c to cycle on and off more often then usuall

 

[nyuk98gt]

rispoli_23:

You're welcome.

And, yes, Sir! The more frequent cycling can be caused by low freon in the system. FWIW, the seals on my compressor wore out and, of course, the freon leaked out. Frequent cycling and not very cold air coming from the vents were the symptoms. New compressor and a refill and, voila, nice and cool. There are also little o-rings in the joints of the AC system tubing. These o-rings can break and allow freon to leave. It is easy to overfill the AC system and doing so can damage the compressor so I suggest a trip to the shop for an expert diagnosis. Not trying to drain your wallet, just trying to keep the total cash outlay to a minimum.

HTH,

Chris

 

[rispoli_23]

thanks ill have a tech take a look at it ...