Hi,

I live in Oz, so the weather is starting to warm up here. The problem I have is when I put the A.C. on when idling, the tach starts going up and down regularly, then after a while it levels out. It doesn't usually do this when the A.C. is not on.

Any advice would be appreciated,

Thanks,

Tim, Australia

Clean the throttle body...same thing happened to me. I had diagnosis that ranged from needed new wiring harness, to any of a number of relays, etc. Finally a 18 year old Volvo mechanic knew, from experience the problem.

I forgot to mention that my car is a 1989 760 with B280F.

I'll check the Throttle Body and see how it goes.

Cheers, Tim

Hello Tim:

Clean your idle air motor too-- then you should be in good shape. There are some idle fluctuations that seem very difficult to cure in the B280 motors, though. New ignition wires helped with mine as well, but as you probably know they are quite expensive...

Good luck!

Herb Goltz, London, Ontario, Canada '92 245 w/165K km

Hi Herb,

I checked the Throttle Body, it still appears clean. I pulled the Idle Air Motor and it looked as if it could do with a clean, so I cleaned it. Idle doesn't fluctuate much now, but it's not as smooth as I think it should be with the occasional hiccup. Do you have any ideas on what could be causing this?

I got a set of wires a few months back as the ones on the car were still the original (as was the distributor,etc. which I replaced).

Thanks for the reply,

Tim