82 320--drove this morning no problem. This afternoon started fine --drove 15 minutes. I did my banking and tried to start the beast. It fires but will not stay running. As soon as I let off the ignition it dies. Any suggestions greatly appreciated.

thanks

Russ

Did you check for vacuum leaks? Check all the lines and make sure one did not come loose.

Yea, start with the oil cap- make sure it didnt come loose or the dipstick didnt pop up a little.
-J

I find no vac lines loose, oil cap is tight, dipstick tight. I wonder if the problem is fuel system related. Is there a fuel pump relay that comes into play. The symptoms remind me of the time when I was believing my optimistic fuel guage and ran out of gas. It would fire but not start. Any thoughts appreciated.

Check the distributor and rotor cap.

sounds like maybe fuel pump circuit related, usually the relay will prime then shut off till the ecu detects crank rotation which wil kick the pump back on. possibly your pump is priming (which gives enough fuel to turn over) but not running after that. maybe relay or crank sensor related. I am sort of new to the e21 and i have webers on mine so i don't how the above directly relates to e21 but most cars have a system similiar to that, hope this helps.

same thing happened to me it was my relay. I posted it as if its not my fuel pump what is it. I jumped the relay and bam that was the deal. 30 bucks later and I was back on the road.

How do you jump the relay, having trouble on a 78 320.

http://forums.bimmerforums.com/forum/showthread.php?t=606386 jumping relay from astro's thread.