Ignition transformer experiences?
#1
Super Member
Thread Starter
Ignition transformer experiences?
So basically my question is, has anyone ever had misfires that were isolated to specific cylinders that were solved by replacing the ignition transformer?
I'm STILL having misfire issues. New passenger coil less than a year old. Just replaced driver coil with a salvage one from a 2010 which appeared to clear up some of the misfires on that bank but #10 is still missing. Basically now I have misfires reported on 1, 3, 4, and 10 only above about 2/3 throttle. Drives like a dream at lower load, But most of my misfires are on the bank with the new coil.
I just replaced all the spark plugs and insulators and gapped them down (in case the higher boost from the tune was just too much for the gap). Basically the only thing left on my list before I attempt to get the passenger coil warrantied (and buy a brand new one for the driver's side as well) is the voltage transformer. The car has brand new injectors as of maybe 5 months ago (E85 conversion), and did drive fine on the new setup for a month or so, so I don't suspect the fuel type change or an injector issue.
Here's what I'm struggling with and really need to know. Everything I've read about the ignition transformer, and common sense also dictates, that in the event of a problem on the output it shuts down the entire output until the ignition is cycled. That's in fact what happened when my original passenger coil was acting up...the whole bank would go dead so the car would run smoothly but just be down on power. Currently, it's just killing the cylinders that are misfiring which results in a very stumbly/unpleasant driving experience until the car is restarted. This leads me to NOT suspect the voltage transformer unless someone else has experienced the exact same thing and found that to ultimately be the fix.
I'm STILL having misfire issues. New passenger coil less than a year old. Just replaced driver coil with a salvage one from a 2010 which appeared to clear up some of the misfires on that bank but #10 is still missing. Basically now I have misfires reported on 1, 3, 4, and 10 only above about 2/3 throttle. Drives like a dream at lower load, But most of my misfires are on the bank with the new coil.
I just replaced all the spark plugs and insulators and gapped them down (in case the higher boost from the tune was just too much for the gap). Basically the only thing left on my list before I attempt to get the passenger coil warrantied (and buy a brand new one for the driver's side as well) is the voltage transformer. The car has brand new injectors as of maybe 5 months ago (E85 conversion), and did drive fine on the new setup for a month or so, so I don't suspect the fuel type change or an injector issue.
Here's what I'm struggling with and really need to know. Everything I've read about the ignition transformer, and common sense also dictates, that in the event of a problem on the output it shuts down the entire output until the ignition is cycled. That's in fact what happened when my original passenger coil was acting up...the whole bank would go dead so the car would run smoothly but just be down on power. Currently, it's just killing the cylinders that are misfiring which results in a very stumbly/unpleasant driving experience until the car is restarted. This leads me to NOT suspect the voltage transformer unless someone else has experienced the exact same thing and found that to ultimately be the fix.
#2
I used to have same problems as you. Misfire on WOT on multiple cylinders. I also have a tune which results in higher boost and more coil pack issues. All I did was change the driver and passenger side coil packs together, along as with brand new bosch iridium spark plugs and spark plug sockets, and everything started to work normally again. No misfires, no problems on WOT, nothing. I did have issues with the voltage transformer before, but that resulted in the whole bank of cylinders 1-6 not receiving power. I do not believe the transformer is related to specific misfires on specific cylinders. When I fixed the transformer, the bank of cylinders started to work normally again. At this point, I recommend getting brand new coil packs and spark plugs, as well as the red rubber spark plug sockets. It is going to be expensive, but you can't really avoid it. These cars are very expensive to maintain. It was 120 grand when it was brand new after all.
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ZephTheChef (09-03-2016)
#3
Have you check the 15amp fuse? From what i have heard, driver side fuse box have a 15amp fuse that can get blow and cause a missfire and it powers coilpacks.. #58.. Mine did missfire 5-7 and change all plugs and wires just because it also need it and a clearing all codes and since then running great.. Still new with the MB world but just doing the research since cant sleep when car is down.. Just my .02cent
#4
Super Member
Thread Starter
I used to have same problems as you. Misfire on WOT on multiple cylinders. I also have a tune which results in higher boost and more coil pack issues. All I did was change the driver and passenger side coil packs together, along as with brand new bosch iridium spark plugs and spark plug sockets, and everything started to work normally again. No misfires, no problems on WOT, nothing. I did have issues with the voltage transformer before, but that resulted in the whole bank of cylinders 1-6 not receiving power. I do not believe the transformer is related to specific misfires on specific cylinders. When I fixed the transformer, the bank of cylinders started to work normally again. At this point, I recommend getting brand new coil packs and spark plugs, as well as the red rubber spark plug sockets. It is going to be expensive, but you can't really avoid it. These cars are very expensive to maintain. It was 120 grand when it was brand new after all.
#6
Super Member
Thread Starter
Have you check the 15amp fuse? From what i have heard, driver side fuse box have a 15amp fuse that can get blow and cause a missfire and it powers coilpacks.. #58.. Mine did missfire 5-7 and change all plugs and wires just because it also need it and a clearing all codes and since then running great.. Still new with the MB world but just doing the research since cant sleep when car is down.. Just my .02cent
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#8
Super Member
Thread Starter
#9
You can rent two coils from him too , if the transformer isn't the culprit
Given the cost of these parts the rental program is ideal for troubleshooting rather than throwing parts at it
Given the cost of these parts the rental program is ideal for troubleshooting rather than throwing parts at it
#10
Super Member
Thread Starter
Since 3/4 of my problem is on the year-old coil that's under warranty from FCP, and I know that replacing the other coil with a newer salvage one reduced the number of misfires I was seeing on that bank, I am quite confident it is in fact a coil issue but I just wouldn't feel right warrantying it on a guess so I do feel the need to rent a transformer (as well as verify fuel pressure even though I'm confident it's not a fueling issue).
I'm headed to the shop now to see what the fuel pressure looks like while it's acting up. If that is stable/checks out, the plan is to rent the transformer just to verify that's not a problem. If it isn't, I will have eliminated: plugs, insulators, compression, injectors, fuel pump/pressure issues, and voltage transformer, leaving only the coil at which point I'm comfortable requesting that FCP replace it, as well as biting the bullet on a second brand new coil from them for the other side (assuming they do in fact honor their fantastic warranty...I have yet to try it).
#11
In that case, it is definitely the coil pack. I think you should save your time and money and just get the coil pack. It definitely isn't the transformer since both your coil packs are still receiving power. I'm telling you this based off my own experiences with coil pack-related misfires and transformer-related misfires.
#12
Super Member
Thread Starter
Fuel pressure is fine. It spikes momentarily when the computer kills the injectors when the misfire starts up but it definitely isn't dropping off/fuel starvation.