95 530i runs rough

First off, I am new to BMWs (and this board) and this will hopefully be my first one. I just got home after looking at a 95 bmw 530i (I am going to buy it regardless its an amazing deal) and the owner says it wont stay running he needs to feather the gas and it idles super rough. But if you get it to idle up it smooths out after 3k rpm. Also while it was idling terribly sometimes it would idle up for a few seconds and sound fine. He just replaced the battery before this happened. Any thoughts? Also a tune-up has been done not to long ago. Thank You ahead of time.

Ok y'all I bought it. It was a great car for about 2 weeks it ran great drove great but then randomly it stalled out and wouldn't start again. I got it towed home where I could start it and move it around the parking lot. Then I drove it about a mile and it died again. Now it wont start all the way but it will kinda start and sputter and die out. I am thinking its the Crankshaft position sensor....Any ideas? It will fire and sputter out so I believe that rules out the Fuel Pump. Maybe the relay?? Alright lets hear some ideas!

Alright, I had a little sunlight left so I took a screwdriver and tapped on the CKS and it fired right up and ran for about 10 minutes. Granted it was a little rough but I think that proves that my sensor is junk and needs to be replaced. If anyone objects speak up now ha. I am ordering a new one on pelican parts in about 5 minutes.

One at a time jeez your a chatty bunch. Part ordered I did 1 day delivery so I will have it Fri. I will update then.

You might have better luck on the E34 forum.

Sounds A lot like Fuel pump or filter or Both about $150 total for both 2 hrs to change both.