Well not too long ago my 94 nissan altima started to run terribly. I tested all of the electrical stuff and didn't find a problem. The cylinder is not firing at all. What else could it be?

 

i would try simple things first...try swapping that cylinder and another's wires and see if the problem moves to a different cylinder. Check your cap and rotor...Does this have the FWD ka24? If so the cap and rotor are 20 for the pair. Try that first.

 

checked plugs, wires, and cap. Getting good spark.

 

Do a compression check, it sounds like you may have a bent or burnt valve in that cylinder if you have good spark and fuel.

 

compression checked out

 

Have you checked the injector on that cylinder to make it's working correctly?

 

That is what i am leaning towards. That or a vacuum leak somewhere on the intake manifold by the injector. What is the best way to test the injector?

 

take the injector out, and hook up a 12v source and if u here CLICK CLICK CLICK its good. if u hear nothing well.. there ya go

 

I would just switch it to a different cylinder and see if the problem follows.