Audio System installed> Misfire detected???

**Ruggedboy** · 08-26-2008 06:25 PM

Hey guys, I’m hoping to get some ideas here as to what’s going on with my car. I installed my audio system this past weekend, which sounds great, but was a hell of a job getting everything in. I finally got to sit back & enjoy the system after so much work; I then decided to take the car out for a spin. The car drives like shit, hardly any boost & I can hear the exhaust note has changed. Now, the thing is I remember reading a post about problems running the main power wire next to the computer. In the end, I made the choice to run a 4 gauge wire right next to the computer. Now I’m wondering if this may have sent a wrong signal to the computer, which eventually sent out a cylinder 5 misfire!
At this point I have swapped out cylinder 5 coil with another coil & for a day that made the difference, but the symptoms came back. I then re-routed the main power wire; it no longer runs next to the computer at all now. I disconnected the coils & let them sit for a while, but the car still runs like shit.
Is this simply coincidence, my coils are bad or is this what happens when you run a high voltage wire next to your computer, any help or thoughts will be appreciated.

**infinkc** · 08-26-2008 07:23 PM

have you tried to drive the car without the audio system power connected? Might be drawing too much power from the batt

**Daft** · 08-26-2008 07:28 PM

Alternator might be smoked and the battery is running the car now. You need to have it load tested.

How many miles on the odometer?

**BITRBO** · 08-26-2008 07:47 PM

Cylinder 7?!?!?!? maybe I read that wrong, but last time I checked we only have 6

**Ruggedboy** · 08-26-2008 07:53 PM

At one point I did try to drive the car with the system disconnected, but there was no change. The only time it came back to life was when I swapped the coils.
Alternator? Wow, I didn't even think this would be a factor at all; I will do a charging system check tomorrow. I have 98000 miles on the car. The main reason I didn't think it was the alt. was do to the fact that it did set a CEL for "cylinder 5 misfire", oddly the light has not set again after I erased it, but symptoms are still there. Also, the batt is new.... Thanks guys, I really hope to get to the bottom of this, I was so happy to have a system & then this!!!

**Ruggedboy** · 08-26-2008 07:57 PM

Shit man, for some reason I said 7. I meant the coil right under the coolant tank closes to the firewall. Thanks for checking me

.

**BITRBO** · 08-26-2008 08:11 PM

no prob. I knew it was just a typo...

GL!

**Daft** · 08-26-2008 08:22 PM

Originally Posted by Ruggedboy

At one point I did try to drive the car with the system disconnected, but there was no change. The only time it came back to life was when I swapped the coils.
Alternator? Wow, I didn't even think this would be a factor at all; I will do a charging system check tomorrow. I have 98000 miles on the car. The main reason I didn't think it was the alt. was do to the fact that it did set a CEL for "cylinder 5 misfire", oddly the light has not set again after I erased it, but symptoms are still there. Also, the batt is new.... Thanks guys, I really hope to get to the bottom of this, I was so happy to have a system & then this!!!

It is very possible that the alternator was on it's last leg or already smoked. The Audio system probably was the straw that broke the camel's back.

I had this problem many years ago on one of my old DSM cars. Damn sub amplifier system ate 2 alternators before I ended up getting a bigger one and more stiffening caps. It even killed my Optima deep cycle battery (red top) in the process too.

**AudiA4_20T** · 08-26-2008 08:25 PM

cylinder 7 can be tricky

**Ruggedboy** · 08-26-2008 08:48 PM

Just read a post of one guy who had a cylinder 5 misfire & found the ingnition control module was the problum, same symptoms as I'm having!
Damn, should have kept the stock system..........