I have run out of diagnostic ideas and am in need of some help. I just finished a complete d16y7 rebuild. Mostly stock except for the d16a6 turbo pistons/eagle rods/cometic head gasket. That stuff should be irrelevant but figured I'd throw that in there before someone asks. Compression is near stock spec, .1 bump.

The engine is misfiring on cylinder 1, hence the p0301 code. Spark, compression, timing, all vitals are good. I've isolated the problem to the #1 injector wiring. I've pulled the fuel rail and cranking the engine will fire injectors 2-4, but nothing on 1. Swap injectors, still nothing on 1 so the injectors are fine. With ignition in "on" there is a 12v circuit from the yellow/blk hot wires of each injector clip to each of their respective colored wires.

Is the ECU failing to run that one injector?

Of course, none of this was a problem prior to the rebuild. Oh, and there's plenty of fuel pressure. Other ideas?

Thanks...

 

Hook up a noid light to that plug and start the car. that will determine if its getting its ground from the ecu.

You can not accurately test the injector with a multi meter while its firing. The multimeter is not fast enough.

 

Either the ECUs #1 injector output or wiring/connection between ECU and the injector is bad, test at the ECU as you already know the injector is not "firing" because of no ground pulse. 94

 

I would check continuity between injector and ecu wire
then ecu as fcm said

 

Injector driver for number 1 looks to be defective. Pull out your ecm and perform a resistance test from the injector wire on the ecu connector to the ground wire for injector 1 in the engine bay, you should have minimal resistance, (1Ohm or less). If you have more than 1 Ohm, repair the open in that wire, if good, replace the ecm with a known good unit.

 

Noid light confirmed pulses on 2-4, but not 1. Resistance test of ground from injector 1 to ECU failed. Replaced that ground wire and everything is good.

Thank you all for your responses. Somehow when the harness was pulled out it must have compromised a weak point along that wire. Haven't inspected the length of the faulty wire yet as I am putting off re-looming the harness until a later date..