I have just installed my 325i running engine , Harness, ECU into a 95 3i8ti. I an having trouble with the Power to ECU relay "chattering" when I try to start engine, and if it starts it runs rough (Relay still rapidly turning on and off). When checking the DME relay with the key switched there is no signal from the ECU to ground (Terminal 86). When I turn the ignition key to start there is a ground on terminal 86 but it is turning on and off rapidly (chattering). I cannot find the wire # for the supply from the ECU to the relay in any manual. I have changed ECU, Fuel pump, Power relay, and also checked grounding system all ok. Has anybody experienced the same problem and have a solution?