Good morning all,

I have a 2007 Mercedes s550 and recently had the intake manifold replaced by my mechanic and now I am getting a misfiring on cylinder 3. I just replaced the spark plug and coil on that cylinder and unfortunately that didn’t fix it. The car has 194k miles and is well taken care of. The fuel injectors are orginal from my understanding. Below is the obd code I am getting. Anyone else experience this? Is it a dead fuel injector or is there a possibility my mechanic might have forgot to plug in the fuel injector? Also if the fuel injector is faulty how hard is it to replace?

 

your title and the picture are not on the same faults

P0303 is called “Cylinder 3 Misfire Detected”

swap the coil stick to the other bank and see if the code moves

the coil sticks on these are a sick joke

 

it’s not the coil or spark .. I replaced both with brand new ones.



QUOTE=BOTUS;9052900]your title and the picture are not on the same faults

P0303 is called “Cylinder 3 Misfire Detected”

swap the coil stick to the other bank and see if the code moves

the coil sticks on these are a sick joke[/QUOTE]

 

oh - I even had my glasses on

P0203 is a fuel injection issue

P0629 high signal level detected in fuel pump control circuit “A”

 

The problem is that is the fuel injector or is the connection? Getting to the injectors is a huge pain in the ***

 

could be either - bad connection or a faulty injector....

the other one might be worth going after first ?

 

The injectors to get to are a pain in the ***?

 

plenty are worse

 

Do you have the part # for the wiring harness that plugs into the injector? I am thinking of replacing that as well the injectors at the same time ..

 

on the main plug by the ECU ?

https://www.ebay.com/itm/146093365045?OE/OEM Part NumberA2731500833, A2730106602, A2711500156, A2730100002

 

Mechanic verified that the injector is connected… now what? Only thing it could be is the injector?

 

measure voltage / signals at plug when running against another
swap injector

don't forget these cars should never run with a misfire Merc CATs are the worlds worst and block for fun

 

Botus,

are there fuses for the injectors?

 

....I would very much doubt it

of course the ECU can do what ever it likes within its software parameters - the other day I thought I saw this Bosch ECU has a software switch to allow / disallow fuel cut off upon cyl error - of course to make it run terrible, smell awful, break the car and destroy the planet - this is always set to throw in too much - like good german design insists upon

 

Ecu is brand new

 

yes, I was stating the std setup - not what is a good idea

Germany builds cars exclusively to steal money and deliberately die - the marketing is phenomenal and with society on a 90 year bender to self destruction - those that aspire to these brand's ethe and now have your money to burn - everything for them is great - so long as they keep ruining the corporations they drink coffee for and exploit immigrant labour - these "leaders" who are both too selfish and too stupid to realise what good looks like - can keep affording to lease them, so reliability is just an unnecessary expense

.

 

No fuses on fuel injectors. It does sound like one of your injectors is clogged, dirty, or just gave up. I'd replace it with an OEM parts not a Chinese look-alike.

 

This car is a labor of love … I would have gotten rid of it by now.. I ordered new ones.. I got oem.. I don’t buy aftermarket parts

 

I totally agree on the labor of love. One thing I have done is run a 20 ounce plastic bottle of Techron on the first day of every other month to keep my fuel system clean and the silly CEL off. Normally, I always thought fuel supplements were simply snake oil, but my S600 drinks six bottles a year, the fuel injectors have not been replaced in 102K miles, and she idles as smooth as a baby's butt.

Just my two cents, but I'd run a bottle of Techron, maybe two bottles, through the fuel system before you replace that injector; and then do it again every other month for awhile. I buy it by the case of six online.

Keep us posted.

 

so from what I gather it’s more a wire issue than an injector issue

 

Possibly a wire, but I would bet on a clogged injector. But as my wife frequently reminds me, WTF do I know. I could be wrong. Let us know what you find and if the new injector resolves it.

 

lol.. well the issue is that the mechanic did the repair and then right out of the parking lot this occurred.. so I know the mechanic is going to say that we should of done the fuel injectors but there was no issues before. The wiring harness has 195k miles on it and I would expect it to not be brittle

 

is there an updated part # to

2731500833?

 

That is very suspicious. I find it hard to believe an injector would decide to fail just outside of the workshop. I can't prove anything and you have to be the one satisfied that the technician didn't screw it up. But I am by nature suspicious and don't allow many strange hands to touch my mistress. I'd have a chat with the technician. If the new injector doesn't resolve it, it means someone manhandled your wiring harness (and didn't admit it). Maybe find a new technician.....

 

Botus,

hep!!!!

Below is my mechanic showing me that power stops going to the injectors on cylinders 3&4…

is there an updated part # to

2731500833?

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