a/c sensor issue

[eclipse96dsm]

hi all im having a little bit of a/c issue was wondering which sensor is the one that makes the idle rise when u turn on a/c to keep the car from dieing out. when i turn on a/c car acts like its going to turn off and sometimes it does so was wondering which sensor is the one that controls this from happening. thank in advance guys.

 

[Vladimir]

Look at a ac schematics. I'm pretty sure when the clutch gets engage it sends the reference voltage to the ecu. Or it could be the high pressure switch because it has the ability to prevent the clutch from cycling on and off. Ecu controls the idle. Also evap temperature sensor has the ability to disengage the clutch.

Also if the engine lacks power and you engage the compressor it would idle a lot rougher, so it could be related to that.

 

[eclipse96dsm]

the clutch cycles on and off perfect except when i turn on the a/c the engine lacks down in idle to like about 300 then stalls. so really idk whats going on. ive tried 3 different ecus already

 

[Vladimir]

Any DTCs present or pop out when it happens?

 

[eclipse96dsm]

well i have dtc as we speak but none are related to a/c

also i havea fully built head with 272 hks cams can that be the case?

 

[Vladimir]

You are running 272s on a stock ecu or is it tuned. Very unlikely that that is the problem, they will make the engine run rough if untuned and if compressor engages engine would run rougher but not enough to completely shut down the motor, I would think. How does the motor run without the compressor working?

It could be that the compressor is locked, and when you engage it it doesn't spin reducing the engine idle speed until car shuts off. But if that is the case you should hear a lot of belt squel before engine shuts off.

 

[eclipse96dsm]

im tuned idle at 800-1000 with a/c off once on bam engine turn off

 

[Vladimir]

I'm leaning to an ecu problem or something corrupting it. Maybe something is getting shorted out causing that, without looking its very hard to say what it is. I dont have ac in my talon so I never experienced that phenomenon before, and working for Chrysler I have never seen or hear of that. Do check the compressor tho to see if its locked, with the clutch engaged, that will put a lot of resistance on your motor

 

[eclipse96dsm]

ok will check that out quick question for the wires on the plug of a/c comp what does ea wire do since there is 3?