ok well guys i'm trying to get my engine running properly and I have damn near narrowed it down to the ecu. For some odd reason, #4 injector does not get fuel.

I have traced the power wires from the injector to the distribution block, to the subharness, then they split in 3 ways. 1 goes to main relay and the other to go to the ecu. All have continuity the whole way and to the main relay.

I have checked continuity for the signal wire from the injector to the subharness then subharness to ecu and they all have continuity.

Everything from the main relay that controls fuel has to run through the ecu first.

So this makes me wonder if the OBDII ecu uses 4 separate injector drivers....anyone got a clue?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98vtec &raquo;</TD></TR><TR><TD CLASS="quote">So this makes me wonder if the OBDII ecu uses 4 separate injector drivers....anyone got a clue?</TD></TR></TABLE>

All of these ECUs have a dedicated transistor to drive each injector, but these are in multiple transistor SIP packages. Look to QM3 and QM4 for a defective transistor.