injector issue diagnosis

[g.k101]

OK guys so a little while back I have having a no spark issue, which got fixed. turns out the "new" PTU was bad right out of the box >.>
I also replaced all 6 coils
So for the record I am getting correct spark, but now I am having other issues and no CEL is on
I got a 91 so early side feed injectors.
i can unplug the pack from cylinder 2 and 4, no change in idle or anything.
for giggles also unplugged the injectors, and still no change. I know They all tested at 12.7-12.9 ohm resistance.
did a fuel filter change too, still nothing is better.
I suppose my question here is, if 2 injectors are having other issues than ohms will the "injector circuit malfunction" code pop?, or since they are connected with ohms that it won't show?

[evildky]

You said you have spark but.... try pulling the cops and plugs from the dead cylinders and laying them on the plenum where you can see them, you'll want to unplug those injectors while doing this. If the injectors ohm good they are likely not this issue, if you verify spark in this manner you can rule spark out as an issue, next would be a compression test. I had a misfire once that turned out to be a cracked valve seat, had fuel, had spark, had good compression but that leaking valve seat caused a misfire at idle.

[g.k101]

If it helps i am currently working out bugs on a full engine rebuild. New sodium filled valves, decked heads (.010" for surfacing) comatec mls head gasket. New cams and gears etc. 168-170lbs in every cylinder. Still ginna try new pigtails. And also i did verify spark via a spark tester. Cool little tool for $5. Just wondering if the cel would pop kn for only 2 injectors not firing for any reason.

[nissanfreak12]

The CEL will not always pop for an injector(s) not functioning. If you are getting spark, then more than likely the Injector as you stated. It is possible the injector is bad even though it test within ohm range. The best thing you can do is replace a known good one, one that is working from anther cylinder and swap it out. If the problem follows to that cylinder, the issue is the injector.

I have had a newer style just stop working, tested at 11.5 ohm. I added power and it clicked, even sprayed correctly. I think the problem was with mine is it was stuck until I added 12v directly to it. it took a few times to actually unstick it. Replaced it and good as new. This is something to look into, swapping the injectors is a lot work, but can help you find the issue.

Just out of curiosity, are you absolutely sure you didn't swap the injector plugs? or Coil plugs? 2 and 4 are easy to mix-up, done that before as well

[g.k101]

not 100% sure other than I know injector #2 has the extra little spade terminal so the wiring harness lends itself to the position. Going to pull my plenum tomorrow, should be easy since I have removed the EGR, PRVR, and coolant line that run underneath. literally 11 bolts and clips and its off. once I pull it I am going to try and unstick them and soak them in a cleaner.
thank you for the answers guys, this really confirmed my concerns.