doesnt start

[jrobie79]

long story, ill try my best: 1991 e30 m42 engine....weird

couple weeks ago i started my car one morning and heard this awful buzzing, didnt seem to affect to much so i continued driving, think its the fuel pump and its on its way out, no biggie ill wait till its dead and hopefully be close enough to home to fix. So it finally dies, i get it towed down the street to my house. Change the fuel pump, nothing.

so i locate the relay and swap that from my sisters exact model e30, hers worked mine didnt so i swapped em, now mine works on her car, but hers doesnt work on mine, so thats not the problem. I hardwire the relay from location 30 to 86, now the fuel pump kicks on but the car does not start... wtf? i put the relay back on and the fuel pump doesnt turn on...bizzare.

so then i dont know why but i think to check for spark, use the spark plug tester i got, NOTHING. no spark, so i change the coil or w/e u call it, with the 4 leads for the wires, i swap em between mine adn my sisters, same deal with the relay. so how do i get my car to start? anyone heard of this before.

[lordofthewaters]

CPS or maybe ECU...........

[jrobie79]

not the ecu, i like i said i have an identical car, so i took my ecu out of my car and popped it in my sisters, hers fired up just fine, took hers which i knew worked, put it in my car, NOTHING.... so frustrating now u said something about the CPS, is that common to go out when the fuel pump does or is that just an uncanny coincedence

[lordofthewaters]

I've never heard of a CPS going out when a fp does, but it can cause no spark.........