Immobilser woes?!

[rugby6or7]

Hi - can you help me?,
We have recently fitted a 1.8 Gti engine from a 2002 Satria into a 2006 Jumbuck, the engine has a Mitsu ECU and the Jumbuck a siemens, we had no luck getting the engine to start (or even crank) with the combination of wiring, so we bit the bullet and changed all the looms - engine, dash and righthand side section which goes through the bulkhead/wing.
Everything plugs in except the fuel pump but we identified the correct wires and corrected them.
All works and it cranks but still won't start!! - I suspect the immobiliser - we have the car's ecu, immobiliser and (triangle) key (the car ran before we started) - we have dash lights but no check engine light and no small led near the key which should light up when you put the key in, I think these problems are linked but have checked and double checked everything.
I thought an immobilser fault would just knock out the fuel pump/injectors but wonder if it is stopping the led/check light powering up - don't understand why as we have all the matching components - please help if you can as I am tearing my hair out !!!!!!!
Thanks
Richard.

 

[Gianni]

Have you checked for spark?
It's the same symptoms as when I put a hg galant motor in my coupe. It was the ecu not being powered properly. Check for fuel pressure. Take off your return line and see if pump is sending fuel. Take out leads and see if you are sparking. Double check everything is plugged in. Find a proton ecu and see if that makes a difference. There might be slight differences in the wiring. if still not starting get a test light out and test your ecu powers

 

[EVO-00X]

Yeah I had a problem with one of the twin relays when I was doing a 4G93P swap some time ago.
In my case the immobiliser was hooked into the white wire with red stripe running off one of the relays. I bypassed the immobiliser wiring and bridged the 2 white wires/red stripe so the relay was fully functional and the engine started.