No Spark 1987 325es

[RobDog]

Hey R3V, I am having a problem with my brothers 1987 325es. The car ran great all day then was parked. The next day the car would not start. The car gets gas but no spark. I also have 86 325es and I have checked or swap the following:

1) Main relay
2) speed and Reference sensor
3) Pin on flywheel
4) Power to coil & swap coils
5) Power to DME pin 18 & 35, swap DMEs
6) Cleaned the C101
7) Plug wires, cap, & rotor (no spark from coil but I was desperate!)
8) Thank you Jlevie your post has helped me keep my families fleet of 6 E30's running for years!

After all that I noticed that the main relay would click on, but when cranking the main relay will click on & off rapidly (wtf). I took the relay out and cleaned both the relay pins & sockets. After this the car fired up but only starts every other day. If we push start the car it fires up every time. Once push started and warmed up the car will continue starting all day. My brothers car runs great for a car with 375,000 miles(when it starts). My brothers 87 325es just spanks my poor 86 325es with 188,000 miles.

What could cause the main relay to act so wierd and what can I do to fix this?

Thanks, Rob

[DesertBMW]

one of the relays have too much resistance in the coil. Once the starter is cranking there is not enough voltage to overcome the resistance. This is why car always starts by push starting it.