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Engine swap done, won’t start

Posted: Sun Oct 29, 2017 6:03 pm
by Jona1971
Hi,
My car was a prefacelift 318i auto and I have fitted a m20b25 with a manual gearbox.

The donor car is the same year (1986) and I drove it so all was well.

I finally got it all connected and ready to fire up today but it won’t start.

The car turns over on the starter.
There is no spark. I have 12v at the coil.
The distributor and rotor are new Beru.

Any ideas where to start looking great fully received :)

Re: Engine swap done, won’t start

Posted: Sun Oct 29, 2017 9:02 pm
by Brianmoooore
Does the fuel pump run when the engine is cranked? Easiest place to check if it's getting power is to make contact with the fuse wire in fuse 11 with one lead from a test lamp.

Re: Engine swap done, won’t start

Posted: Sun Oct 29, 2017 9:26 pm
by drakesmith
Something is not earth. Very simple mistake

Re: Engine swap done, won’t start

Posted: Sun Oct 29, 2017 9:31 pm
by Brianmoooore
drakesmith wrote:Something is not earth. Very simple mistake
There's only one, and that's the brown/orange from the engine loom, with a ring terminal on the end of it, which goes to the earth terminal on top of the RH suspension strut.

Re: Engine swap done, won’t start

Posted: Mon Oct 30, 2017 6:04 pm
by Jona1971
Oooh, the only wire I’ve got connected to the battery’s earth is the fat earth wire from the car strut tower.

I’ve got 2 black sleeved cables from the engine loom with rings on the end. Does one of these go to earth then?
How do I know which is which?

Feels like I’m getting close now....


(I’ll check fuse 11 too)

Re: Engine swap done, won’t start

Posted: Mon Oct 30, 2017 6:46 pm
by Jona1971
I had this one connected to Earth.

Image

...and both of these connected to live. One comes from the fuse box and the other from the engine loom. (The engine loom one is too short to reach the negative terminal.)

Image

Re: Engine swap done, won’t start

Posted: Wed Nov 01, 2017 5:39 pm
by Jona1971
Anyone?

Re: Engine swap done, won’t start

Posted: Wed Nov 01, 2017 10:43 pm
by drakesmith
They are ground wires. Did the engine come out of a sports. Battery in the boot?

Take off the covering and see what colour the wires are.

Re: Engine swap done, won’t start

Posted: Wed Nov 01, 2017 10:58 pm
by Brianmoooore
drakesmith wrote: Take off the covering and see what colour the wires are.
Red go to battery + terminal, and brown or brown/orange go to the battery negative terminal on the strut tower.

Re: Engine swap done, won’t start

Posted: Wed Nov 01, 2017 11:12 pm
by drakesmith
Or get a test light and test if both are live or earth or one is live and one earth. The battery will have to be connected to test this. And probe the two wires.

Normally if wire are live they are not exposed. Only earths are bare.

Re: Engine swap done, won’t start

Posted: Thu Nov 02, 2017 11:42 am
by Jona1971
That’s good info, thanks all.
Yes, the donor car had a battery in boot.
I’ll have a go at the weekend and report back a™‚

Re: Engine swap done, won’t start

Posted: Sat Nov 04, 2017 1:47 pm
by Jona1971
UPDATE:

The wire from the fuse box to the battery is now connected to LIVE.

I peeled back the insulation on the other one and it was RED so I connected that to LIVE too.

The EARTH from my older car engine loom is next to the alternator. I cleaned up the rings and the surface and reconnected it to EARTH.

The car turns over and I fitted a test light to FUSE 11 which lights up when cranking the engine.

Any ideas? (no spark)

Also, what's this?

<a href="http://s1380.photobucket.com/user/jonat ... t.jpg.html" target="_blank"><img src="http://i1380.photobucket.com/albums/ah1 ... zhnhpt.jpg" border="0" alt=" photo IMG_3569_zpsh4zhnhpt.jpg"/></a>

I don't remember it being connected to anything before. It comes off a wire from a sensor in the bottom of the engine block and another end that goes to the injector loom...

Re: Engine swap done, won’t start

Posted: Sat Nov 04, 2017 1:48 pm
by Jona1971
Image

This, sorry...

Re: Engine swap done, won’t start

Posted: Sat Nov 04, 2017 2:08 pm
by Brianmoooore
Does this car have the two crank position sensors in the bell housing?

Re: Engine swap done, won’t start

Posted: Sat Nov 04, 2017 9:41 pm
by Jona1971
Yes, and I had them connected the wrong way round.

I swapped them over and it fired up first time.

a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚

Re: Engine swap done, won’t start

Posted: Sat Nov 04, 2017 10:42 pm
by Jona1971
:D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D

Re: Engine swap done, won’t start

Posted: Sat Nov 04, 2017 10:57 pm
by drakesmith
Woop woop. Happy days

Re: Engine swap done, won’t start

Posted: Sat Nov 04, 2017 11:07 pm
by Jona1971
:D

Re: Engine swap done, won’t start

Posted: Sun Nov 05, 2017 1:10 am
by Brianmoooore
Jona1971 wrote:Yes, and I had them connected the wrong way round.

I swapped them over and it fired up first time.

a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚a™‚
You're one step ahead of me! :thumb:

Re: Engine swap done, won’t start

Posted: Sun Nov 05, 2017 6:50 pm
by Jona1971
LOL.

Thanks for your help
:D