EJ22 in a kit car just added A/C

[pvenuti]

I have a 1992 EJ22 that I’m running in a replica Porsche 356. Standard engine swap stuff original computer and harness cut down to the minimum number of wires. I Just added the remanufactured A/C compressor and seem to have that all set up blowing nice and cold. My question is this. With the remanufactured compressor there is only one wire(used to engage the clutch on the compressor). When I turn on the A/C the compressor kicks in and loads the engine sometimes stalling it if at idle. On the original Subaru harness there are three wires going to the compressor. One presumably would normally be used to engage the compressor does anyone know what the other two are used for? Any chance I should be connecting one of these to my existing single wire so the computer knows to expect the extra load from the compressor? Or does anyone know how the EJ22 system knows under normal(in the original car) conditions to handle the extra load.

 

Thanks

[capn_r]

Yes one of the wires from the computer increases the idle speed with the compressor engaged. I don't recall which and I'm not where my manuals are. My foggy memory is coming up with plug c pin 9 but I could very well be mistaken. If you don't get it sorted let me know and I will be a bit more definitive when I get a look at my FSM and notes from my swap.

[pvenuti]

Thanks capn_r for the response. If you can look at your FSM and let me know what you find that would be great. At the plug for the compressor I have three wires Red with yellow stripe (cut at the plug let’s hope this isn’t it). Blue with red stripe intact running back to the harness and Yellow with blue stripe. Too bad the colors in the wiring diagram I have in my Haynes manual don’t match up..

Edited July 20, 2010 by pvenuti

[pvenuti]

Anyone have a sugjestion for this.

[capn_r]

It is the blue with the red tracer stripe. If you put +12v to that wire the idle speed will increase.

[pvenuti]

Sweet, I will give that a try.

 

Thank you very much for the help

[pvenuti]

Any chance it's the other wire Yellow with blue tracer?

[heartless]

ok, here is a wiring diagram for the AC system from a 1990 FSM - it looks like it could be the yellow wire you need to use...

 

warning - LARGE file!

[pvenuti]

I'm trying that wire now and it does seem to make a bit of a difference. Hard to say because now I have some new intermittent issue. Got a code 33 vehicle speed sensor yesterday don’t have one of those hooked up. I cleared the code by disconnecting the ECU it was the only code. Now even though its over 75 degrees when I start the car it idle varies. Last night drove it about a mile idle was too high say 1800rpm stopped for 20 minutes drove it home still too high.

 

Got up today drove it 2 miles idles at 2k even after the car is warmed up. I shut the car off go into the store come out 45 minutes latter car is still plenty hot start it up idle is perfect at 800. Stop again 5 minutes idle is at 1100. I haven’t had the air on at all today these fluctuations in idle started occurring after I reset the ECU. Any suggestions?