Why is #4 cyl misfiring after new plugs,coil. if I unplug 4 coil nothing happens on 2008 Nissan Altima

It just started running rough. #4 plug was real black and gummy when I replaced it. Every so often there is blow by smoke when he starts the car. if I unplug any of the coils the engine nearly shuts off, but if I unplug #4 nothing happens. Is it the fuel injector?

by in Columbia, MD on August 18, 2014
1 answer 2 comments
ANSWER by , August 18, 2014
Compression reading was??... Noid light flashing when testing # 4 injector pulse??... # 4 coil actually producing spark when tested with spark tester???
COMMENT by , August 18, 2014
I'll have to get these checks done. Right now the check engine light flashes on and auto zone stated the code said #4 cyl is misfiring.
COMMENT by , August 18, 2014
Yeah, got to do some more testing to get to the bottom of this one!... Start with the compression test.!... That's the main thing at this point!