525tds

i've just changed the engine on my 92 525tds touring for a 94 engine & i've had lots of compatibilty problems. I'm using the engine wiring loom and the DDE for the 94. However the car runs lacking power, the heater plugs don't work, the fuel water light stays on and the rev counter only goes to 2000rpm. I did initially try the 92 wiring loom & DDE but the engine wouldn't start. Can any one help?