any help please, 1998 1.4inj civic wont start ive got spark at the plugs,fuel to the injector rail,no electric pulse to the injectors so fuel is returning to tank ,is the a relay for the injector circuit?the fuel is pumping to the rail so no fault there,are the injectors a permenant live with a switched earth from the ecu? if so and i have no permenant live what could be the cause

 

Yes the injectors are permanently live on one end and the ECU drives the other end to ground when needed. This power comes thru the main relay mounted near the ECU. Note that the relay will only be closed when the engine is actually detected to be rotating or the starter is activated, it drops out if the key is on but the engine is stopped. The relay unit has a little circuit board in it and it is common for the connections on the board to fail. But the same relay drives the fuel pump too so it is kind of unusual you would have one but not the other.