RotorDream

Ok, before you guys start talking crap:

1. I already searched but couldn't find anything except things remotely similar that I already checked.

and,

2. Although I have a PFC, I posted in here because I don't believe its related.

Now, to the problem. I recently had the A/C repaired on the FD, including a new expansion valve and dryer. I've had no A/C at until now, and only because I moved back to TX and driving in 108F weather with an all black leather interior, isn't very fun, regardless if it's an FD or not (It's pretty hard to enjoy the drive when your squinting to keep the sweat out of your eyes, and your hand keeps slipping off the shifter). When I first got the PFC I did the idle learn minus the A/C part for the previous reason. When I went to the shop to pick it up, I noticed the problem, here are the symptoms/non-symptoms:

The good:
Idles fine without A/C and electrical loads 750rpm
Idles fine with electrical loads 800rpm
Alternator voltage is between 13.6 and 14.1
Brand new Optima Yellow top
Runs great (no backfiring, stalling, idle hunting) without the A/C on
Runs good (alittle power loss, but I believe this is normal) with the A/C on while driving.

The Bad:
As soon as I turn the A/C on the idle drops to between 480-510 but its not really "hunting"
Alternator voltage drops to 12.0-12.2 (I believe this to be due to the drop in RPM, but correct me if I'm wrong)
Car will die if the A/C is on and come to a stop while driving

Now, here is a list of what I have checked:
TPS voltage - within limits of FSM
Idle screw under the throttle body - tried adjusting between 1/4-3/4 turn out
disconnected the IACV - same symptoms.
tried idle learn process with every combination of PFC O2 feedback on/off, IACV connected/disconnected
raised and lowered idle settings on the PFC

I did notice that with O2 feedback on, when the idle drops it pulses at about a one second cycle between the 480 and 510rpm.

This is really making me
I need a fresh set of eyes on this one. Let me know if you have any Ideas!!!!!!

Edit: Not sure if its related but I did notice awhile back that the idle would drop about 20 rpm when the wheel was at full lock in either direction. It hasn't done that in awhile though, so I kind of shrugged it off. Mazda reman with about 35k

RotorDream

ok. I just came across a thread that said something like the airpump might somehow be causing it, so i just disconnected it, same problems. checked the compressor, turns pretty easily by hand, seemed difficult due to how i had to reach it, but easy enough it shouldn't bog down like it is. adjusted the idle screw under the throttle body, and now the idle is around 720-740 with the compressor running enough that it doesnt sound like its about to stall, but as soon as i turn the A/C off it jumps to around 900 and drops back down to 800 and settles out. seems like its working ok, but i know it shouldn't be doing this, so i still want to find a solution.

RotorDream

Ok Nvm. after 3 1/2 hours and 2 red bulls I figured out the problem, and it was not really related to the PFC, but kinda was. apparently when pulling the 4 clips out of the harness I inadvertantly pulled the IAC clip slightly out aswell. I am guessing I never would have noticed untill now, since the idle for the electrical load isnt much higher than the base idle, and its not like i have use my defroster alot here in TX. Well just goes to show you what you can accomplish with the FSM the body electrical manual and enough Red Bull and Rockstars! haha


Mods please close this thread.