E28 starting issue

[Eagle]

Awhile back while driving my 84 525i along the road i had a sudden loss of power so i pulled over and stopped, when i tried to start up it wouldnt so i ended up getting towed.

I thought it could be either the fuel filter clogged because awhile back i nearly ran out of gas so i changed the filter, it started fine and easy but after about 5-10 seconds clonked out and it would start again just keep turning over.

Could this be the fuel pump\relay or maybe the DME relay?, it was hard to start before this happened.

E28 has 3 relays beside the fuse box, anyone know what one is which. 1st on is 6 pin and the other 2 are the same

Any advice appriecated
Thank you

[Eagle]

can only hear the pump buzz for about 1\2 a second also

[BillionPa]

it could be a ground wire come loose, that would cause loss of current during start, and if it loosened, a good drop in power (or a stall) and refuse to start after.

if you havent replaced the 2 main relays, do it anyway.

the fuel pump relay should have 7 pins, part 264.
however, if there are 2 orange relays in there, one is for the fuel pump and the other is for the O2 sensor.

it could also be ignition related, either the distributor parts or the ignition coil, or perhaps the spark plug connectors.

check inside the distributor, if the dust cap under the rotor looks cooked, other parts such as the vacuum control system could have become contaminated with metal particles.