86 325es no spark... Help!

[Tay131]

Alright guys, first m20 just came to me Saturday. Test drive her for 45 min, ran great besides the sloppy shifter bushings, and broken exhaust between the cat and muffler. So I bought it, 15 minutes in to the hour drive home going 70-75mph 3200rpms, she cuts out and wouldn't accelerate or rev.
So I got her towed home, she's getting gas, no spark... So I changed the battery, main relay, the cap and rotor, coil, spark plugs and wires, CPs(CPs was spinning and wiggling but not coming out easy, Took a couple hours of sitting there, butch was jammed hard) Still no spark... I changed the ground from the rear of the valve cover to the engine bay battery tray, as the old one wasn't looking good. And the ground in the trunk to the battery... Still nothing... Any ideas?


Also we found a 3rd wire maybe a ground? Going to the coil but the end was nt connected to anything... It wrapped around the passenger fender around the back of the motor, and then went under the fuse box but wasn't connected to anything my buddy said it went thru the fire wall but I looked under and there's no wire ripped/cut the same way



Help? Please and thank you

[sayed ali]

Try another ecu, and before that i guess you have short in somewhere which may burnt the ecu ..

[RobDog]

I just had this promblem with my brothers 87 325es. Double check your main relay. I checked the main relay first, it tested good ( so I thought ). I then went through the long list of other things it could be and found nothing. Only after his car kicked my ass did I realize that the main relay would click on and power everything up, but when cranking the engine the main relay would click on and off rapidly.

Other things to check are:
1) Ecu pin 35 and 18 have power from the main relay.
2) Ecu pin 1 grounds the coil. Make sure that wire is not broke between coil and ecu.
3) Reference sensors in bell housing
4) Pin on flywheel the reference sensor reads off of. Take sensor out and look in the hole for the pin while someone turns the engine over. (This happened to my sisters e30 and it was a bitch!)
5) Check spark from coil to eliminate wires, cap, and rotor.
6) Check power to coil from ignition switch.
7) Swap ecu's for a known working one.

Thats all I can think of right now. Good luck and welcome to R3V!