Hi all,

I have the following problem,

When I have my airconditioning switched on the engine stalls.

Now this does not happen all the time.

When the car is in motion, with varying revs, there is no problem.
The problem only occurs when I have to brake or slow down to allmost standstill (speedbumps for example)
At the moment the revs go down from 2500 plus, to minus 1000 and then it seems the airco is consuming to much power and the engine stalls.

Now the engine (2,8 V6 30 valve ACK code) has, in my opininion a very low idling rev (around 500 Rpm) and it looks like that is the problem.

Does anybody know how to increase the idling speed on this engine?

regards

Luke

 

If I'm not mistaken: The idle air control valve controls idle speed (there should be a diagram under your hood), but I don't think that's your problem. It sounds to me like your A/C compressor is going out on you, which is causing the car to stall under low idle, but not when you're "powering through it"..

 

Could be, not sure.

What I did notice though, is that the normal idling speed (without aircon on) allready is very low (about 500 / 600 rpm), there where it should be around 800 or 900 rpm so I figured if I could increase that a bit that would also increase my margim for when the engine is revving down with airco on.

And it looks like it is a matter of 50 / 100 rpm...not much.
Comparable to a carburator that has been adjusted to lean

Just found a Kris Hansen article about how to dismount it, has the cleaning any particulary issues I should be aware of?


Luke

 

I had this on my old Audi A6 back in 2005. After replacing virtually every electronic part on the engine, which included the ECU (which didn't solve the problem), it turned out my aircon compressor's bearings had seized but weren't making a noise, so this was never checked or even suspected.

Each time I would come to a sharp corner, and my car's auto transmission would gear down from 4th to 3rd, and while turning the power steering, it would be too much load and the car would cut out while driving around the corner and I'd lose braking and steering at the same time. Quite scary.

Start your car and let it idle. The idle should be around 800 rpm, but you say it's already low. When you switch the aircon on, the ECU recognises the idle must "step up" to accommodate the load - but if the load is too heavy, it won't be able to accommodate this and your idle will actually drop to around 500 rpm (well, that's what my car did).

I would seriously have the aircon pulley checked out. Even my A4 is now starting as I can see when I turn on the aircon, the idle drops and then comes back up, but its a matter of time before I must replace the compressor. It's about 14 years old, so it makes sense it has worked pretty hard.

It's worth a look