88 E30 Stalling/ re-start problem

[crews]

Ok- I need some direction here- my daughters 88 E30 ( 325i/ auto sedan) has an issue that I cannot seem to isolate.

When she starts it up in the morning ( or anytime after it is warm even) and lets it idle for any length of time, the car will shut off and the battery is dead.

I have checked the alternator and it seems like it is charging- even at idle?

Once it is jump started, she doesnt seem to have any driveability issues.

Any thoughts on where should my troubleshooting be focused?

[jlevie]

Seems like the alternator is charging or actually is charging. If the alternator is working correctly system voltage will be ~13.5v at idle rising to ~14v at 2500rpm. Additionally an aged or bad battery could be the problem.