KA24E #2 Cylinder Dead?

[cbt240sx]

I have a 1990 240sx with a KA24e. I was driving one day, stopped at a store, everything was fine. When I got back in the car and started it up, i noticed a change in idle and it sounded a little rough. Thinking I had an injector go out, I replaced the injector with a known good replacement only for the problem to persist. This is in cylinder #2.

I have read through several threads pertaining to this particular problem but most of them stop short after someone has replaced an injector.

This is what I have done so far as for troubleshooting:

1. replaced spark plugs and wires. Cylinder #2 has spark.

2. Swapped injector #1 with Injector #2. Both injectors work when in the #1 cylinder, but I get nothing out of cylinder #2.

3. replaced injector plug at the harness, it gets about 13v at the clip when testing with multimeter, but idle doesn't change when plugged up to the injector.

4. Checked the ECU for corrosion, there was none, looked brand new in there.

Is there something else that I am missing that would keep the injector from pulsing or spraying fuel into the cylinder? The spark plug doesn't have gas on it when checking, but I do have spark.

I have a compression test kit but have not checked compression yet as it seems like an electrical problem to me. I have a timing light but have not checked timing yet either...

If anyone would care to chime in, it would be greatly appreciated. I drive this car like grandpa and am not hard on it in any way. The car has been great since I bought it in 2007. The KA has about 151k miles on it and thus far has been extremely reliable. I am by no means a master mechanic but I do have the aptitude to fix this myself before paying someone.

Thanks!

[cbt240sx]

Bump for Boobies! ♥ (o)(o) ♥

[ricebike]

#3 is conflicting somehow... you did verify the injector working in #2

& had a signal going to the 2nd injector plug...

is it also 13V from another injector plug???

[compactfean]

All 4 injectors get power from the same source. The ecu grounds each injector. Rather you have a damaged harness (run your own wire to the ecu) or the ecu is bad.

[cbt240sx]

Thanks for the replies.

#3 is conflicting somehow... you did verify the injector working in #2

& had a signal going to the 2nd injector plug...

is it also 13V from another injector plug???

Strange how it could be #3. I redid all of my plug ends and they all get 13v on all plugs..

All 4 injectors get power from the same source. The ecu grounds each injector. Rather you have a damaged harness (run your own wire to the ecu) or the ecu is bad.

I guess my next step is to run test wires ecu and see if that will help. But would I still get a voltage reading at the plug if it were an ECU/Wiring issue? Thanks guys.

[compactfean]

There are 2 wires to an injector. just because the injector has power (one wire) does not mean the ecu is able to ground the injector to make it fire (the other wire). Get how it works?

[cbt240sx]

There are 2 wires to an injector. just because the injector has power (one wire) does not mean the ecu is able to ground the injector to make it fire (the other wire). Get how it works?

Thanks for clearing that up, I figured it had to be something of that nature. I do have power but I honestly don't think it is firing, which would explain why the injector that was in #2 works in #1 and the one from #1 will not work in #2......also the plug isn't wet with gas when I checked..

Looks like Ill be running a new set of wires to the ECU and see what happens.

Thanks again!

[compactfean]

Its only one wire. If it is a bad wire, it should be a very quick fix. If its not the wire, its the ecu.

[cbt240sx]

A little late, but the issue here was the ECU. Replaced it and it purrs like a kitten.