No Spark on #4 Cylinder
No Spark on #4 Cylinder 
Thursday night my car ran rough but didnt think anything of it. And on Friday morning the SES started to blink/ran rough but stopped after a mile. Today the SES blinks/runs rough all the time. i went to Autozone and got DTCs: p0304 and p0354(coil)
At Autozone, I switched the coil from #4 to #1 and scanned it again with no change. I repeated the same with the plugs and wires. Still had misfire on #4.
I then unplugged the #4 wire from the plug and started the engine and got no audible clicking noise or visible spark. I did the same with other cylinders and got noise/spark.
Got a test light and checked the main coil harness and #4 connections pink wire and got light.
What else can I do to find the problem? Thanks
found what could be the problem.
the main coil harness connector (male) is no good. the missfire fluctuates between the #2 and #4 cylinders when the connection is wiggled. going to the dealer to order one
the main coil harness connector (male) is no good. the missfire fluctuates between the #2 and #4 cylinders when the connection is wiggled. going to the dealer to order one
not necessarily the coil...actually I am willing to bet it is the #4 injector. When the SES blinks, it is a code that is considered more severe and usually has to do with the fuel system. I actually work for autozone, so I know you got that free test! lol....but a flashing service engine soon light points more towards a severe problem. See, when the injector is faulty the incorrect amount of fuel is being added to the cylinder. Because it is flooding, or spark knocking due to lack of fuel, the knock sensor picks up the erratic firing. The computer tries to adjust for the lean or rich condition on that cylinder in order to "smooth" the running condition out..basically shutting off the knock sensor signal. If you switched the coils and there was no change, more than likely I would point to that fuel injector. 8 times out of 10 this is what we find to be the cause. In fact, I have checked this in our parking lot many times. Best way to do it is to pull the plug on the trouble cylinder and then pull a plug on a known good cylinder. Look to see what the difference is. If it seems like there is an excess of fuel, the injector is stuck open. If it is a brownish white color...and dry. It isnt opening. Also, if you pull the injector out...and have someone try to fire the engine...you can tell if the injector is working properly or not. (not recommended to do without someone near by)...try these tips out and let me know what you find!
Did anybody elses cars start acting F*ing crazy when the temp. dropped outside? My car is running like ****. Code throwing machine. Light didn't just come on...it flashed several times while rpms dwindled at <400rpm just stummblin' away. Never died but I was ready to start walkin' my A$$ to work it seemed like several times. No mods. All stock here. Going to check it later with HP Tuners Pro. logging software to pull codes. Runs like a scalded ape when driving...but come to a stop and it runs like a cammed car from the 60's....RUTRO!
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