1983 533i no spark

I have no spark,no injector pulse,no coil pulse.I have checked reference sensor,and engine speed sensor=ok.main relay puzzles me,the blue/red wires to ecu have 12 volts until i crank then my test light goes dim.also the fuel pump fuse does not light even while cranking.im thinking of replacing the ecu next,just wanted to see if anyone else has come across this.thanks

Originally Posted by brianrig

I have no spark,no injector pulse,no coil pulse.I have checked reference sensor,and engine speed sensor=ok.main relay puzzles me,the blue/red wires to ecu have 12 volts until i crank then my test light goes dim.also the fuel pump fuse does not light even while cranking.im thinking of replacing the ecu next,just wanted to see if anyone else has come across this.thanks

Check all the cables coming off your battery terminals and especially to and off the starter. Try jumping the fuel pump and or ECM. I wouldn't replace it yet. The connections to the fuse box and the fuses are known problems. Get yourself a Bentley's manual. It has comprehensive test procedures for the main relay, injectors, etc.