Have you checked the relay for the engine ecu. This relay is also a yellow one. I had a fault on my cossie 4x4 where it wouldnt start and it was the fuse holder for the fuel pump relay. The connections on the fuse holder were corroded. The electrican cut the fuse holder out and put a new one in. He was on 20mins lookin at my car and he cured it in that time.