Problem with the sparks ... :/

[poop12]

Hello ... for starters I am Christian and I am new to the forum and a new holder of the M42;) recently ... yesterday I swapped my m20 with an  m42 in my 84 320i ... but the problem is that there is no spark ... and I  wonder what’s the problem … I think I reconnect correctly the harnesses but I’ll double check it  … what could be the problem ?

thanks

[DesktopDave]

They made a lot of changes to the C101 harness connector (The big round connector on the firewall from the body harness to the engine harness).  You'll have to get the right pinout diagrams for the body and re-pin it a bit to make it all work correctly.

I have a similar problem, putting an M20B25 into an '86 325e.  Won't start yet.

Welcome to the club!  Your english is very good, BTW.

[poop12]

Yesterday I went through the topics ... and I think I will handle the harnesses  ... I saw that I was wrong about some cable ... I hope that this will solve the problem

[poop12]

Proud owner of an WORKING m42 … so I checked the harnesses and they wer perfect ! … I cranked a little bit but … nahhh nothing … so after that I taked the spark plugs off and refit them … crank-nothing … so I switched spark 1 with spark 2 and 3 with 4 ( because there was some other numbers on them so I tried to use them ) after that I cranked  and then BOOOOOMMMM a relay strong bang … I checked exhausts and around them it seams ok and I cranked again thre was 2 more bangs ….
Then I switched the sparks again and the job was done …  it rawrsssss veri nice