the car won't start
 

All spark plugs and ignition coils replaced with new ones. the car won't start normally. it only starts when the gas pedal is pressed to the floor, but the engine jerks terribly, checks appear and misfire errors are posted below.


https://cimg8.ibsrv.net/gimg/www.mbw...590eae3da.jpeg

Sure looks like your Voltage Transfromer is shot. Symptoms are usually all the plugs on one side misfire. Clark Rupp sells one called the boost box which uses upgraded components and moves it to a cooler spot than on top of a hot engine. Easy to replace it but it costs about $675. His products are quite good. Keep us posted.

Thank you for your interest in my problem, can you tell me what part number I should buy and where to buy it?

V12 or V8 ? - V8s don't have a separate voltage transformer

the generic P0300 misfire is interesting

the others are the faults you get per cyl if a coil stick isn't working....

If its a V8 are you sure you fitted it altogether OK - didn't muddle wires to each coil stick etc. ? if its a V12 usual fun

v8 Model: 221.086 engine m273. I don't think it's even possible to confuse the coil cubes. But everything is connected properly. and new spark plugs and coils were installed because the car drove normally into the garage and could no longer be started. But replacing the plugs and coils did not help. To start it, the gas pedal must be on the floor, then it starts, the engine starts and the errors I mentioned above appear.

so a V8 - with each cyl having its own coil stick - they are quite basic, if it ran OK before and you swapped all for suitable viable parts then I'd look for wiring faults (particularly if you put the old bits back and now it still has the same fault conditions)

It wouldn't surprise me if the engine loom is all crispy and snapped wires - what mileage ?
what (if any) other parts did you disturb - you can do all 8 coils sticks inside 30 mins - with plugs and a bit of extra cleaning 1 hour

hang on - you did the work and drove to a garage where it all went wrong ?

did you fill with fuel ?

check the receipt did you fill with diesel ? or check social media - its quite common for a garage to miss-fill their tanks - the best way to find out is everyone else saying their car is dead too...

you misunderstood. I drove the car every day and it was ok. Once upon a time there was a problem with the engine starting to shake and there were misfire errors. But the car was turned off and started again and it drove for over a month and everything was fine. It went into the garage and the next day it couldn't be started again. so the mechanic replaced the spark plugs and coils in the garage. and as for refueling, there is definitely fuel in the tank, not diesel.

ahh - in the post it would have helped changing the words the garage, to a workshop

interesting - just today a thread about CPS (crank position sensor), these wear out and cause interesting fun....

dead coil sticks normally stay dead, so if they were playing up it won't start normal next drive - but a CPS can and regularly does perform like that.
we don't really know what the workshop has done..... and in my experience parts for these cost so much people tend to accidentally borrow your working parts for themselves - landing you with fun when you get your car back
if we think they are legit -

at the miles you mentioned it might be a CPS that caused the strange running - but now its snapped wires to the coil sticks making a big misfire with codes


.

ok, so you need to check the cables to think and look further.

So sorry, I thought it was a V12. V12s have a VT. Not V8s.

Keep us posted.

I would also comment that V8s are famous for using Crankshaft Position Sensors (CPS) and if yours is older than say 45K miles or if you just don't know how old it is; I would replace that first and then work on your ignition system one coil at a time, Usually, you notice a CPS at a fuel stop. When you try to restart a warm engine - nada. Wait 30 minutes for a cool down; and she starts right up. After that over time (days) it simply fails and no start.

thanks for all your valuable advice. the spark plugs and coils are all new, it doesn't hurt that they were replaced. I will check your and previous advice and let you know. I hope you can find the cause. because it's strange that the car was working properly the day before and suddenly it didn't want to start the next day. But about a month ago there was a situation where the engine suddenly started to misfire and there were misfire errors, but after turning off the car started normally and drove for a month or more without any problems. and now with new coils and candles it is the same as before the replacement, the car does not want to start, only when the pedal is pressed to the floor it will start, but it throws the errors that I added in the photo and throws the engine.

CPS is not expensive and not hard to install. There have been other posts with the procedure you can search including good pix. Check the part number but this is typical: https://www.fcpeuro.com/products/mer...r-642153072805

You're right, considering what I spent in the world and coils, it's not expensive. If only replacing it would help and the car would start normally and the ignition wouldn't misfire.

this newer wording makes me think you should check this video -



from a reply in this post https://mbworld.org/forums/s-class-w...sometimes.html

Following this thread, did you try replacing the CPS?

I have the same Issue
 

I have the same issue exactly the car was randomly misfiring when I drive it I turn it off then start it again the misfiring gone but yesterday I tried to start it, it was misfiring alot and turn off by itself and when I check the code it show the same codes all the cylinder’s misfire so if you find what the issue please help me with it

Have you guys verified that fuel pressure is correct when cranking?

Crank position sensors are a wear item. Knowing how they are inclined to fail the E-55 got one every two years.

When flooring the gas pedal helps to start the engine it kind of points to flooded cylinders OR improperly atomized fuel spray. This then leads to possibly having too low fuel pressure that the previous poster also mentions as an item to check.

that was the case where cars had a real, mechanically operated butterfly - but with flyby wire nothing happens to the butterfly in the throttle body - it stays full closed (and a flooded engine get worse and worse, as the pedal give no air but even more fuel) - but maybe this points to the pedal sensor being messed up ?

she in doors did a short 25 yard drive in a 2002 VW golf and switched it off - next day the car wouldn't start - jammed the butterfly open with a screw driver, had the plugs out and neat fuel spat out the plug holes - perfect after that - to say my advice to hold the revs up at 2k rpm for 2 mins before she switched it off was clearly heard (as it should be on any singe start !!!) and my 40 mins pulling engine covers and plugs was 100% necessary !!!