I know nothing about injectors and cannot find anything on this subject. I know that stock E55 injectors will work on a C32 and just about every other 55 AMG motor but I am not sure about the C55?


Will the stock E55 injectors work on a C55 and if they do, will I need or not need to mod anything?


Thanks

 

Anybody?

 

I am so frustrated! I have looked everywhere on the internet and the forums and cant seem to find any information on what other injectors will work on a C55. I know its a M113 motor but the E55 has different heads. I don't want to buy some that are higher flowing (like E55) and mess up my motor.


Can somebody give me a hint on who to ask about this or where to go?
I would really appreciate it .
Will the ECU need reprogramming etc.


Thanks!

 

Do you mean W210 E55, or W211 E55K..??

ZAYED,,

 

I don't know to much about E55's but I do know its a 2005 as well. Also, I always read of people upgrading their injectors on the C55's but they don't specify anything else? Do you know what else I can put in that will not require an ECU program? My C55 is an 05 W203.


Thanks for the reply

 

W210 E55:- (217cc)

W203 C32K/W211 E55K:- (396cc)

R171 SLK55/W203 C55/W209 CLK55/W220 S55:- (283cc)

*As you know; little lean if you go with W210 E55's, too rich if you go with E55K's, i'm not sure if ECU/data E-prom can be programmed with E55K's..?!!?

*i never heard anyone upgrade any N/A M113 injectors, i believe it's not worth it..!!

 

Ok, so you are saying that I cant upgrade from stock on the c55 and I have to use a 233cc or the car will run rich and I will get a CEL? It is so confusing because I have been looking at 550cc injectors on Ebay and the ad text says they will work on the E55 or the C55?


R171 SLK55/W203 C55/W209 CLK55/W220 S55:- (283cc) it is


Thanks for the info

 

The 550cc injectors would work as far as the fit is concerned, but without proper mods and tuning, it would not give you any benefit. Go with OEM or the C32/E55K injectors. The ECU will adjust (up to a point) if it sees larger injectors. Smaller injectors will run at 100% duty cycle which is not a good thing.

 

Hi Lenin,


So you are saying that I "can" run the larger E55K injectors and the car will run fine with no CEL light? The ECU will adjust fine?


Thanks

 

Yes, that's what I'm saying. Best choice is OEM C55 injectors. Next are the black E55K injectors. In 2006 E55K came with a blue injector that flowed a bit more than the pre-2006 E55K. The ECU will adjust just fine. To make larger injectors flow more fuel the ECU maps need to be adjusted (re-scaled). Otherwise the ECU monitors the AFR and adjusts the injector duty cycle (and some other parameters). I'm oversimplifying things, but the main point is that you will be fine with injectors that are capable of flowing a bit more fuel. You do need to get a full set. You should not replace just some of them.

 

Perfect! I am looking for a used set of injectors and there are a lot more E55K's available then C55's. The E55's are also a lot less expensive for some reason. I guess it is just supply and demand lol..


Thanks everyone for your help!

 

Lenin,

I don't think go with bigger injectors in N/A aspirated M113 is a good idea,

cause ECU-prom data will reads more +fuel vs -air, and that will interrupt the MAF back signal to the ECU,

need more air to re-calibrated with more fuel rate, this can be done with air boost in "SC or turbo" Engines,,

how to increasing the air in N/A Engines to match more fueling...??

ZAYED,,

 

Why you want to upgrade your injectors?

Dont go bigger injectors if they are more than 10% larger.

 

I agree that the ECU will see more fuel initially and I'm thinking that it will adjust the IDC and therefore less fuel will be delivered to maintain the proper AFR. I just don't think that it would be such a big deal but you may be right. It is true that it is tuning forced induction cars is easier. As I said earlier, the OEM C55 injectors is the best choice IMO.
If that is how you and Zayed feel and have direct knowledge, then I'm learning. I just didn't think you would get much more fuel in without reprogramming the ECU.

 

I have the E55K's and was wondering if they would work? What would happen if I put them in a N/A motor? Has anybody done it?


The injectors are both the exact same size and OHM resistance is the same as well, what distinguishes the two? How would the ECU know that it is a larger injector?

 

Good point Lenin,

but as you know; when you put more injector cycle/flow, ECU will recognizing more fuel vs less air,

then it will save that more fuel amount in the "E-prom/Rom data",,

that will cause RICH mode, more fuel will wash the O2 sensors/less life for spark plugs/MAF density reading will interrupted via randomly ECU faulty signals..!

ZAYED,,

 

I think it's too much fueling rate from 283cc >>396cc, need more air boost to reach that much fueling in N/A Engines, that's why 32K/55K got more cc/lh injectors,

*no any benefits will gain with more injector cc without air pumping...!!

ZAYED,,

 

Understandable, but what makes one flow more then the other if they are both the same size and OHM? Is there a spring inside that is firmer then the other to compensate for the extra combustion? If that is the case, you would think that it would run lean because the spring would not actuate enough to allow enough fuel?


Also, I am not really looking for a benefit, I just want it to work because I already have them and don't want to but others.

 

There is a different spec. of "solenoid coil valve" inside, which controls the flow on/off,,

i believe, better idea, if we can find 6 or 8 holes VS our 4 holes with same cc/lh injectors...!?!

ZAYED,,

 

I think I found the difference. I am getting the pics now. Stay Tuned

 

It looks like they are both the same except the size of the spray tip holes. So I believe its not the injectors but the ECU to compensate for the extra fuel? Its kind of hard to see but the black injector has larger holes.

 

What is wrong with your injectors? If they are not working correctly you need a direct replacement or get them cleaned and flow tested. There is absolutely no benefit at all from changing to larger injectors on a stock or NA modded M113. I don't know mercedes specifics but in general most ecu's will not be able to compensate in open loop mode and you will run very rich. They can compensate to a degree in closed loop via O2 feedback.

If your engine is going to run lean because you have too much air flow ie you have a turbo or a supercharger kit then larger injectors and a full ecu recalibration is required. I don't know the specifics of these particular injectors but usually the pintle and seat etc are larger to allow more flow. Outwardly they should look more or less identical- which they do in your picture.

Fuel flow is determined by the injector flow rate at a particular fuel pressure and duty cycle. Your fuel pressure regulator controls the fuel pressure. Your ecu controls the duty cycle. Your injector flow rate is a factor of the particular injector at a standard pressure.

 

^^Excellent Input^^

ZAYED,,

 

+1 to tw2's comments

Putting it simply:

As we all know, your cylinders get an amount of air and fuel to cause the combustion. It's designed very precisely depending on how much air your intake flows in and how much fuel your injectors input to complement that air. The car's ECU is designed this way.

Adding fuel to the mixture with the same amount of air, as stated in above previous posts, will not do anything but cause you to run rich, which would actually hurt you.

You can only inject more fuel if you input a proportional and calculated amount of air (i.e. turbo or supercharger). And this has to be calibrated via ECU tuning. You can't just "guess" when you're screwing with this kind of stuff.

To put it simply, it's not a simple process. I think you should get rid of the E55 injectors and get OEM replacements.

 

Please don't see this as an attack but for the sake of discussion. Here is what will happen if the injectors were used on a stock M113- I don't know the flow rates but taking what ZAYED has mentioned.

The ecu thinks it has 283cc injectors so knows just how many milliseconds of duty to give at any particular throttle position, rpm and MAF reading. The ecu is calibrated to the 283cc injector. You have 396/283= 1.4x larger injectors so the engine will be receiving approximately 40% more fuel than was intended. This will wash the oil film from the cylinder walls causing scoring, it will foul the spark plugs, it will ruin the cats and also the oxygen sensors. Power will be much reduced.

Some of this effect can be tuned out by adjusting the fuel tables but I don't know if it could compensate for the extreme difference. I know the supercharged guys have a lot of trouble with adjusting the resolution of the stock MAF. Even so, no one is wanting to spend heaps of money on tuning to get back to where they were before.

The other thing to consider is that most OEM applications have significant head room as far as injectors go. They usually only run somewhere around 60-80% of maximum fuel flow rate when the engine is making full power. This means that there is still a lot of scope for increasing power without needing new injectors. This is more than enough for headers, intake, port/polishing, cams, ecu tuning, almost anything on an NA engine. Of course when you increase your volumetric efficiency 50-100% with turbos or superchargers then that head room, is instantly gone and 400cc and larger sized injectors are needed.