Need Help CSI SVT Cobra (w/PICS)

[roushstage2]

I need some help diagnosing a problem with my 03 Cobra. The dealership told me that cylinder #4 was skipping, although I could not tell a difference in how the car ran. So about a month ago I purchased a new stock sparkplug and installed it. When I removed the old one and the terminal was completley rusted over so I figured the problem was the sparkplug.

Well this weekend I removed the plug to make sure everything looked alright, and the plug looks like it has not even fired at all.
Here is a pic of the #4 & #3 plug (this is a month or so after I installed a new plug)

Here is another photo of the plugs along with the coil, notice how the coil from the #4 plug is brown (also it smelled like gas)

So what I did is I installed the plugs back into the same cylinder, then I swithched the coils between the #3 & #4 cylinder. I figured when I checked the plugs again if the plug looks different then the problem is the coil.
Today I checked the plugs again and I found that the #4 plug looks exactly the same as it did before, meaning its not the coil thats the problem.
Here is a pic of the #4 plug after the coils had been switched.

Anyone have any ideas on what I can try next, since I know its not the coil or the plug?

 

[pb1302]

Well if you are certain that the car has spark....... check for fuel...... Could be a clogged injector and no combustion is happening. Or the gap is way off from the other ones....... did you actually see if the spark plug is firing by pulling it out and hookin it up to the coil and starting the car? Could be that the wire going TO the coil is not doing its cob of providing the juice......

 

[roushstage2]

Well if you are certain that the car has spark....... check for fuel...... Could be a clogged injector and no combustion is happening. Or the gap is way off from the other ones....... did you actually see if the spark plug is firing by pulling it out and hookin it up to the coil and starting the car? Could be that the wire going TO the coil is not doing its cob of providing the juice......

The reason I thought the problem was coming from the plug/coil and not the injector is because that plug has been in the engine for around a month and a half and seems that is has not fired at all (the white ceramic color is just as white as when it was installed). Shouldnt the white change colors if the plug is firing?

I did not try taking the sparkplug out and starting the car. Will that cause any type of problem if the car starts and there is no plug in there? If not that will be the next test I will try.

As for gap, I measured the gap of the #3 & #4 cylinder when I had them out.
They are:
#3- 0.046
#4- 0.043

 

[blue88mustang]

Does your oil smell like gas? If so, then your #4 injector is probably working fine and you are not getting spark.

If your oil does NOT smell like gas, then your injector could be clogged, unplugged from the harness or just faulty.

I would double check all the connections going to the injector and the coil. If the problem still persists, then I would say you either A) have a bad injector and/or wiring to the injector or B) have a problem with the wiring that plugs into the #4 Coil.

 

[fordracerguy]

Believe me, if a cylinder is not firing, you will KNOW! The car will run rough as all $#(*$. I had one of my fuel injectors completely clog on my Cobra. Took it to the dealer, they replaced the plug and coil and said here you go, all fixed. Started it up the next day and it was rough again. So I replaced the injector myself, and all was fine! Go out and get an injector and be done with it. I'd also switch the coils one more time. You may have thought you switched them yet putting them in the same place??