I have a 91 RS 305 TBI with 5 spd.

Car runs perfect when the AC is kept off or if I'm just using vent fans/Defrost. However, when I kick on my AC it bogs down a lot. Makes it shift rougher and it sounds like the engine is trying a lot harder. My question is does this sound like the AC compressor is going bad or does it sound like just the clutch on the compressor?

 

Sounds like normal operation to me. Our factory compressors suck the life out of these cars; it's absolutely rediculous how much power they pull. Double check to make sure your throttle kicker is activating with the AC and keeping your RPM's up. Other than that, there isn't much that can be done other than some modding to get one of the Sanden compressors to work.

 

Yes my throttle kicker compensates for the power lost by the A/C and keeps the RPMs good at idle. Is it possible to reduce how much power is being lost by using some kind of lubricant to run through the A/C system or by getting a new compressor? I like having the A/C but I don't use it often and just realized a few days ago how much power it's really sucking from my engine.

 

. May not be the A/C, but a loss of voltage to the computer when the A/C is also engaged... make sure battery negative terminal is well grounded to engine, frame, body, and the ground strap from rear of engine to body is there... make sure 14.2 volts at battery when everything is turned on and engine running... battery clamps/connectors making good, clean contact at battery terminals...

 

Interesting idea. I'll make sure to check my grounds and get a multimeter on my battery to check for possible issues with power.

 

Unfortunately, there isn't. Our compressors just suck power. Even my 300hp 350 noticably powers down when the AC is running. Unfortunately, my AC doesn't cool very well, but that's a different issue.