so my 86 325es with m20b25 head / 2.7i stroker block wont start. it has a new battery which replaced a smaller one which gave me problems the day i bought it , since the car didnt run for ten years before the P.O. bought it , it would start up weird and idle kind of weird. but since i'm driving it every day now that issue hasn't popped up fortunately. But today after dropping one of my friends off i go to turn it on again , it starts up noticeably unusal 
, i turn it off to see if it would start like then , sure enough , it did. So i drop off my last friend at his house , turn it off , turn it back on again . doesnt start , wont crank or turn over . after i had my friend jump start it , she started like normal . I go back home , park it , turned it off , test started her again . same issue.
btw, the lights turn off when i try to start it and the sound it makes when you turn on the electronics fades down when i try to fire it up . what could this be? what can i do to fix this?
located in san diego.
, i turn it off to see if it would start like then , sure enough , it did. So i drop off my last friend at his house , turn it off , turn it back on again . doesnt start , wont crank or turn over . after i had my friend jump start it , she started like normal . I go back home , park it , turned it off , test started her again . same issue. btw, the lights turn off when i try to start it and the sound it makes when you turn on the electronics fades down when i try to fire it up . what could this be? what can i do to fix this?
located in san diego.