oneofone

I have a moderately Modded 07 GT. (see garage for mods) I am having misfire problems. It started out twice a month, now its once a day at least. It has been all over the board which cylinder but has mostly settled on #3. sometimes it just codes and you dont feel it, more often than not it shuts the cylinder down for 30 seconds or so and you feel it. It does it under all sorts of driving conditions, cruising at 45 with no stopping all the way to hammer down. I have replaced the coil, and plugs. had injectors professionally cleaned, and had tune checked.
Any help is appreciated!

Nstaley

What mods do you have? Did it start to happen after installing one of the mods?

oneofone

no, mods have been on for over a year. this started about 8 mos ago. Detroit Rocker Cams, Steeda Underdrive pulley, long tube headers off road H pipes, airraid CAI, 93 tune.

A side note is I have replaced the alt two times in one year and this last time the power wire with the fusable link to the battery was burnt on back of alt. Replaced it. Dont know if it has anything to do with it or not

Nstaley

Did you change the plug wires as well? And what do you feel when it misfires?

oneofone

no just coil pack. well it just sluggish and rough. like i said it shuts down the cylinder to prevent it from getting damaged then clicks back on after about 30sec. ( my mechanic is the one who told me that it was shutting down the cylinder when I described it to him)

Nstaley

Well, it might be the plug wires because a bad wire could cause the connection to be bad causing it to misfire. If it's shutting the cylinder down, it might be because it's not getting the right connection it needs. But it could be something completely different. I thought my engine was bad but it ended up being the catalytic converters were clogged causing it to run very rough.

oneofone

yea I hadnt even thought that way. i checked new wires are only 100 bucks so i may just toss them on to see what it does. That could be whats causing me to have alt problems if its draining it from a short. Cats are deleted so I know theres no problem there

Nuke

What COP's did you install? Most aftermarket COP's have been problematic. OE COP's are the way to go unless you're FI and even then the gain is marginal.

oneofone

@ Nuke. Yea they are all oe. I only replaced the one on cylinder three that was having problems. didnt do anything to help. I was only trying to fix the problem. not looking for HP gains....well not there anyway LOL

tx_zstang

Are you getting a CEL and reading codes for a specific cylinder?
If this started occurring after you replaced the alt. wire, that could be an issue. But you could have a bad alternator as well..again.