S52 swap cranks but no start.

[SoloMid]

S52 from a 1999 m3 swapped in to 1990 325is.

Swap is obd2 with dme tuned by markertmotorworks cranks fine but doesn't start. No fuel or spark when cranking. New spark plugs and fresh 30 litres of fuel.

Fuel pump turns on when relay is jumped but still no start when main relay is jumped with fuel relay. Lines are not mixed up m50 manifold and fuel rail feed to the front return to rear where the regulator is.

Tried 2 harnesses c101 spliced myself wiring was all double checked. Tried new Fuel and main relays.

One strange thing is that with both harnesses the battery light is always on when the key is removed. Battery is 12.45v maybe something about the alternator but wiring is ok and probably wouldn't cause no start.

I'll update with anything new but any help would be appreciated.

[328ijunkie]

Verified power at pin 7? Harness have power and ground?

[SoloMid]

Yes power at pin 7. Harness is grounded at passenger shock tower and 2 connections at battery terminal thing.

For starter using e30 cable.

[328ijunkie]

There is one main power feed for hanesss and one main ground. Try using main battery terminal for power feed instead of small fusable link one

[SoloMid]

I tested the small fusable link one before and it was fine but I put both connections to the main battery terminal just in case and still the same thing.

[328ijunkie]

I tested the small fusable link one before and it was fine but I put both connections to the main battery terminal just in case and still the same thing.

Upload a pIc of your power/ground connections... Hanesss doesn't need much as far as wiring goes to start car...

[SoloMid]

Sorry if images are too big.

So 1 ground and 2 e30 connections (starter and fuse box) and 2 S52 harness connections (one to o2 heater relay and other to DME I think).

[328ijunkie]

You have power at red and green wires at green relay shown in pic?
With key on

[SoloMid]

Only the red wire not the green. My first harness didn't even have this relay...

Tested with 2 relays.

[328ijunkie]

There should be 2 greens going into that relay, does either have power? If not your c101 connection is missing something

[SoloMid]

Dumbest mistake in the world lol I got this second harness and I was trying to do things fast so I just chopped all 3 X20, X69 and X6031 off when splicing the new C101. I went over the wiring for it again and found out there were 2 same gauge green wires and I connected the DME EWS green wire to pin 7 on the C101 instead of the DME power.

Thanks a lot for your help 328ijunkie I don't think I coulda got this started without you. I'm sure this electrical stuff is super basic to you but I'm not really good at it to appreciate it!