I NEED some SERIOUS HELP!!!! PLEASE

[Z3gundam]

OK, you guys have been very helpful in the past and I am so very greatful to be a NISMO owner.

N E Ways, I push a 1993 240sx hatch base model 2.4l motor ka... w/ a few mods (cold air and stuff of that nature). Well this morning it was driving fine, then all of the sudden at a red light, it started running a little rough. Its like it was skipping.

About a week ago I upgraded to a 255 walboro fuel pump w/ z32 filter. Back in November I changed the spark wires and replaced all 4 fuel injectors. Now the motor is running rough.

So I went on ahead and change all 4 spark plugs, rotor button and cap. It is still running rough. I figured out it was in cyclnder 4. With the new wire and plug it fires fine, but its not like its firing in the head. When I pulled the old spark plugs, they were kinda burnt but the 4th one was completely black.

I also smell gas when I drive it. Also, can anyone tell me the spacing between the arc and the thing on the spark plug. I forget what they call it.

Any thoughts, all advice will be greatly appreciated. Thanks in advance.

[compactfean]

The spark plug gap should be on the emissions decal under the hood, oh that thingy is the electrode. What is your fuel pressure at?

[Z3gundam]

I looked under the hood for that sticker that would tell me the gap for the plug but didnt find any. I have no idea what my fuel pressure is. How do I find that out?

[AZhitman]

Your plugs are likely pre-gapped from the factory.

Pull the #4 plug out. Connect it to the plug wire. Hold it with the threads grounded (against something steel, not aluminum) while the engine is running and look for spark (helps if the garage is darker or you're in shade). Something tells me #4 isn't sparking.

[Amays U G37S]

If the car sounds like a V8, and sometimes it kicks up and runs normally, you may have a bad injector. I know you just replaced them but if you bought used, then ya you probably have a bad one. If you bought new, you could still have that problem.

[OutToWinPAHC]

Your plugs are likely pre-gapped from the factory.

Pull the #4 plug out. Connect it to the plug wire. Hold it with the threads grounded (against something steel, not aluminum) while the engine is running and look for spark (helps if the garage is darker or you're in shade). Something tells me #4 isn't sparking.

This or that new injector is allowing to much fuel or sticking open.

[Chaluska]

im going with sticking injector..

or leaking o-ring.

unplug your injectors (one at a time) and see if any changes happen..
If the injectors are operating properly, when you unplug them, the idle will drop to like 200-300 rpms, and barely run, quick test.

if you unplug one injector, and the engine start to idle better, that could be the leaking injector.

or if you unplug one injector, and NOTHING happens, the idle still remains crappy, i would look there for fuel issues..

or if you unplug all of them, and no change is noticed for any injector. i would then look to spark issue

[Z3gundam]

Thanks for all the help so far. I'm going to do some trouble shooting with the injectors. Also when I pulled the 4th plug back out, it was completely black. That was a new plug. Do you guys think that might have anything to do with it?

I also did what AZhitman said and it is sparking pretty good.

[AZhitman]

Then do the injector test. I should have thought of that first.

[NicUzumaki]

u can also run the car, turn it off, then unplug all four injectors and try starting it, if it starts up and runs for a decent amount of time then the o-rings are definitely done for
napa or lordco sells em fairly cheap

[Z3gundam]

OMG.....Dudes, I appreciate all the help. NISMO heads like you guys make me proud to roll nissan. I got fixed, it was the feul injector. I have no idea why, it was a brand new injector thats only been in for 5 months. Go figure.....

Thanks for you guys help.....

[OutToWinPAHC]

Stick around and you will see what becomes common... I don't own a KA or an SR but I have diagnosed many of them just from seeing what others have experienced. The good thing is these cars are not so bad to work on.

[Amays U G37S]

Sucks to hear they are only 5 months old, but sometimes it happens!

Glad we were able to help. Good luck!