Spark problem or iono?

[alnissan]

Ok hi guys my new(to me) 92 coupe isn't running right, the fourth cylinder isnt firing. I checked the spark plug and replaced it with no difference. I switched the 3rd and 4th plug wires and no difference. I can take the plug out when it is running and it makes no difference. I haven't checked compression yet but what do u guys think?

[sportzguy38]

Most likely its the injector its a common problem with the 240sx. To make sure what you can do is switch the injector from cylinder 4 with the injector from another cylinder and see if the problem changes to the other cylinder.

[alnissan]

Thanks ill try tomorrow maybe and see if that works. Ive searched for this prob but couldn't find anything 'bout it.

[S13xCrazy]

Nah, you don't even need to check. I can guarentee its an injector.

This is a common problem. Happened to me to