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!

Frank_Jaeger

How do you know it's cylinder 2?

iveexcaped3

so when you swapped injectors from 2 to 1 the idle smoothed out? if that is the case why did you switch them back? if it didnt fix it like frank said how do you know its #2

cbt240sx

Pulling the plug wires and injector clips off while idling in cylinder 1, 3 & 4 just about kills the car. Pulling the plug wire and clip on cylinder 2 does nothing to change the idle. That's how I know it is #2.

As stated, both injectors work when in cylinder 1. I can switch them all day long. Cylinder #2 does nothing no matter what injector is in there.

Frank_Jaeger

Did you try pulling the plug wire on cylinder 2 while injector 1 & 2 were switched?

cbt240sx

Yes, this has been done while troubleshooting. Both injectors work perfectly when in the #1 position, neither injector seem to work when in the #2 position, despite getting voltage to the injector plug\spark plug. I'm like...dafuq.

iveexcaped3

when is the last time you replaced cap and rotor? it almost sounds like its not fuel related, do you have access to noid lights and a injector testor?

Pro ViZIon

Have you checked for spark?

__________________
1990 Nissan 240SX w/KA24DE - New project
1984 Mazda RX-7 GSL-SE 13B

cbt240sx

I have never changed the rotor or cap, I have spark on all cylinders. I have a bag of injectors I need to test, It has to be an injector...but I just don't know at this point..It seems as if the injector is stuck or not pulsing/spraying fuel...but that doesn't explain how the injector that was in cylinder #2 is now working in Cylinder #1 and the one that was working in #1 is dead in #2......

The spark plug didn't smell like gas when I took it out..I still have some testing to do.
I need to just pull the fuel rail off and see if all 4 injectors spray fuel, then go from there...


Or I could just bite the bullet and take it to a shop.....It's just hard for me to trust a stranger with my car..

iveexcaped3

Get some noid lights and test the injector plugs, it might have a shorted ground going in and out some where so when you test for power it has it but cutting out. That's what the noids are for a shops gonna do the same thing.

Touge180

Id check the compression and that will give you your answer if you have good compression then its got to be a spark problem.Also run a volt meter across the number 2 injector and see if your getting 12volts.