how to tune engine idling with or without air cond

[Aero]

Hi thereHaving some question on engine idling tuning, or tuning,as i am facing drop in idling when the air cond is switch on.is it normal or is there anywhere i can tune the idling with or without the air cond. possible what will be the ideal rpm range.by the way is there way to adjust the air fuel ratio?please advice.

 

[jarance]

Aero, what model and year?

Normally, cannot adjust cos it is usually self adjusted by the ICV.. The normal idling speed should be around 750 to 800 rpm.

 

[Lionel_Koh]

if u facing drop after on d aircond ...most probaly ur ICV got problem ......

if ur car is e30, 34, 36 then u can adjust ur idle thru a nut at throttle body .......others model im not too sure ......

 

[Aero]

sorry, mine is a e30 m40 1989, please advice adjusting the nut on the trottle body is just adjusting the trottle cable. correct me if i am wrong.

what i am thinking if there is a seperate adjustment for the aircond idling, as it drop when i switch it on.

Any other adjustment for this engine. or how can i know if the icv is out, or how to adjust the AFM if required. had clean the icv,trottle body and also the AFM.

no idea what else i can check.

Please advice.

 

[cempaka]

Get your ecu wire loom checked. There is a wire that is supposed to signal when the aircon is turned on which tells the ecu to raise idle slightly to compensate. If missing or not connected, it will cause this problem.

 

[Aero]

that will be a tricky one, any comment on how to identify and to be exact where ?

Please guide if possible.

 

[jarance]

PM fabianyee or kevster30. They are the sifu when it comes to E30.

 

[elwine30]

tune without the aircon 1st. The E30 M40 should be about 700 +/-.

sometimes,even if you clean your ICV, your ICV may not work. It's not your AFM.

 

[jarance]

Okay, forgot the other sifu, elwine30.. LOL..

 

[Aero]

elwine 30 how do i identify whether the icv is out and should i tune the idling on the adjustment on the trottle cable.

can advice be specific. thanks

 

[jarance]

There is a quick way to check ICV function.

At idling speed, disconnect the cable from the ICV. If there is no change in the RPM, chances is that the ICV is not functioning.

Pic of ICV connector

 

[Aero]

thanks for the advie will check the ICV, but how about the tuning for the air cond idling any can advice this too.

 

[Aero]

as there anyone can advice further, would appreciate.

 

[elwine30]

u need to troubleshoot bro. idling issues can be very subjective. best bring yr car to mech to yr mech to sort it out,

 

[kevster30]

Aero,

I can confirm with you now that it is one of these:

1) ICV no good
2) Vacumn leak in your induction system.
3) AFM no good

On a m40 system, the idle of the car cannot be adjusted. Idle is determined automatically on a Motronic system with/out AC on/off. If you play with the throttle adjustment, you will upset you throttle position sensor(TPS) calibration. If you don't know what this is then you should not try to DIY. Google can be your best friend.

Same thing happens when you try to tighten the accelerator cable. There should be a 1cm slack on the cable at rest as it should not put and pressure on your throttle at idle position. By playing with the cable you are only influencing the position of your throttle butterfly and will in turn influence your TPS's readings and values, which will send inaccurate info to your ECU.

You do not have an adjustment problem. You have a mechanical problem. Good luck in your troubleshooting!

 

[Aero]

thanks, would hope this will really assist. in this cse diy is not the best solution, any suggection on having it fix. please advice.

 

[Aero]

its been a more then a year and i have yet to solve this problem, i did send to a mechanic and i was told that the air cond compressor was too big for the engine to pull, the question is the idling does not increase when the air cond is switch on, rather it actually drop.

clean AFM, ICV, Trottle body, and i dont know what else i can do......

 

[johnj]

Send your car to Bluegreen motor werks ( same row with the firefighters building before motorola, federal highway ). they will settle for you.

 

[Aero]

Send your car to Bluegreen motor werks ( same row with the firefighters building before motorola, federal highway ). they will settle for you.

will try then out one day, guess i went to the wrong place all this while.