Hey all, When I turn my aircon on, my idle (if you could call it that) goes from around 900 to about 1.5k. What should I be looking for to fix that? I have fitted a brand new AAC unit, but just to note the aircon idle problem was there before the AAC was installed. Apart from that, my idle is rough as a turd. 900, then drops to 700/600 then back up again. Popping and farting away. It's really annoying me. I'm tempted to organise a tech day. I'd supply beer I have a boost leak tester but I'm afraid of blowing my seals out. Thanks, Marc.
1500rpm isn't unusual(1250-1400 is about normal with AC on). as for BL Tester, you're not trying to inflate a tyre, just 4-5psi is way more than enough pressure to use the Tester(and that won't harm your seals).:zlove:
Nah, the idle raises too much. It pushes my car when I'm going slow. Its like I got the thottle stuck open in a traffic jam. Datascan showed my Tps @ 0.45v. When the car stumbled the o2's would flick all the way down to rich then go right back to lean (a value of 90+) Should they be like that @ idle?
could it be the compressor bearing is it possible that the bearing in ur a/c compressor is seizing or getting harder to turn, thus the car is bumping the revs up to give it an extra kick. Just a thought i had
Who told u that Travis?? Cause its wrong !! They work from Idle up to the start of the open loop part of the fuel/ignition map.
Might swap my O2's then. I have a brand new set spare, even though the ones in there are only about 6000k's old. They were wired up wrong though with the heater element wire connected to the O2 signal wire :?
Don't worry about the O2's Marc, they have no bearing on idle speed whatsoever. Make sure your idle speed is set correctly along with your base idle timing first. The ECU uses the AAC valve to add additional air to compensate for the load of the A/C compressor.
That's not correct Graham. When the ECU receives a closed TPS signal it uses a specific set of variables for that alone, it does not use the primary fuel or timing maps at all. If you have ever done any work with a Wide Band O2 sensor on a Z, you will see that typical AFR's at closed TPS sit around 12-12.5:1, depending how K-values and latency is set for the injectors. If the O2 sensors were working and manipulating the ECU, AFR's would be a lot leaner as you are aware of being lambda 0-1V which equates to 14-15 AFR.
What controls the idle when the Aircon is on. Well I should say, what determins the rpm increase when the aircon is on?
Yea, but I've replaced the AAC valve. So I guess the ECU is telling it to go too high...damnit I don't know how to fix that.
Do you have Datascan Marc? It's really hard to correctly diagnose your issue from 1500km away without some actual feedback variables to go by.
And to add to this thread. I'm still misfiring. I've checked all the coil packs, changed the CAS, changed the Cold Air Valve, Replaced the AAC, changed the AFM, changed both O2 sensors and replaced various old vacuum lines. This is becoming a real pain in the ass.
I notice u didn't mention spark plugs ? changed them latley? Do u have another PTU to try out? Regards Trev
I changed the plugs to idiriums when I got the car about 12,000k's ago. I also replaced the series 1 PTU with a series 2.
How long ago did it start missfiring? idiriums foul pretty easy. How bout trying some standard copper jobs? won't cost much to try Regards Trev
It was quite a while ago. I put up with it until now cause I want to finish off the car and get it tuned. I checked a plug from both banks and they're the light brownish/gray colour they're ment to be. But I'll get some more plugs and swap them.
To add to this, I have replaced all the coil connector plugs, the injectors were cleaned and new plugs installed during the plenum pull when I got the car. I have no error codes and a new battery.
