BMW 540i 1997 auto

my car stalls when the auto is put into reverse, the problem is intermitent but worse when the air con is off. Can any one offer a suggestion with this problem.
thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Idle speed is too low. (air con pulls it up by ~200rpm).
If slightly earlier one might have suspected Nikasil.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.