Joseph Pelayo

Hi everyone. First time posting on here.
Ok so here's my problem.
Passenger side entire bank is misfiring . Codes 300-306. 5 months ago I replaced all the spark plugs and both coil packs. Was running beautifully until until yesterday. I have lifetime warranty on the packs so I replaced the pack and plugs on it . Nothing. So I took it to the dealer and 4 hrs of diagnostic labor later after checking it out. They can't figure out the problem. Idk what they checked . I took of the cat thinking it might be plugged but no difference. So car turn on both banks but after 15 seconds passenger side bank shuts down.

kraut56

check out both forums with "search".

Ignition inverter is most logical part to look at.

Joseph Pelayo

Can a Mercedes-Benz Star Diagnosis System (SDS
Detect weather that part is functioning? Or does it have to be manually tested?

tusabes

It seems SDS cannot differentiate between a coil pack problem and transformer problem

Since the coil packs are new the next step is the transformer . All these parts should be replaced anyway at this age

Joseph Pelayo

Just an update. So I put in New plugs and coil pack and nothing. So next I'm going to put in a new ignition inverter. Wish me luck

Astro14

Before you spend $700+ on an inverter, I recommend that you rent one.

http://www.v12icpack.com

These guys have a rental program - and I just had them repair my passenger side coil. They are a great alternative to replacing parts (repair and/or rebuild your coil instead) and the rental allows you to troubleshoot your problem without throwing parts at a problem.

ZephTheChef

When my coil went out, it started out as you described, that bank would sometimes shut down after running a while. But usually would hit on all 12 if I shut the car off and restarted. Then eventually, it would not come back on at all. At that point I parked it and ordered a new coil. It's been fine ever since I replaced the coil with the exception of when I have the water/meth spraying. I'm not sure yet whether it's actually causing a misfire, or if the computer just thinks it is and shuts down a bank after the fact. It seems to do fine during a pull but sometimes will shut down one bank after I get off the throttle.

I was thinking of doing the ignition transformer rental to see if it cures the problem. It's entirely possible that the water/meth is just messing with the ion current stuff and triggering false misfire readings in the computer. Seems to run fine if I unplug the water/meth pump. I opened up my transformer and couldn't see any bulging or leaking capacitors or obviously cracked/bad solder joints but that's about the extent of my diagnostic ability with electronics.

Joseph Pelayo

It was the ignition transformer. I used the rental program that astro recommended . They Sent the part in 2 days. So I'm going to keep it.

Astro14

That's great news! Glad to hear that you've fixed it.

shooffnyc

This is good to know. I will give them a try also. Certain mornings when I start my car, the entire passenger side misfires. It always happens in the morning when there is alot of dew in the air where water droplets form. After driving some time, it would go away. I am not sure if it's the ignition transformer or some of the coils have bad contact due to the moisture forming.

Renting the parts will give me the best way to troubleshoot the issue. I'm glad to know this program worked for you as it gives me more of a reason to give them a try and save some bux. Thanks!

Joseph Pelayo

Yes it's great. He will let you keep it up to 10 days until you have to return it.