BMW 323 Injection

[Sandy]

This is a change of pace for me, I just got a 1980 BMW 323i Alpina with a
great 2.3L 6 cylinder! One problem with it however, is that the idle is
unstable. It will 'motor boat' up and down, usually stalling out. Other
times it is stable. I haven't as yet found out much about the system, I
think it is a bosch j-tronic, it is all mechanical, fuel distributer, etc.
Any ideas where to start looking?

Sandy