Venom55

Hello MB world,

I had this issue recently where my car suddenly act so weird and start accelerating and breaking at the same time!? And sometimes hard to start engine, it goes after i turn it off and turn it on again.

I tried to search the net about what is exactly going on and i found some people that have exactly the same problem, but the bigger issue i ahve is that every one have different kind of fix !!

I am not being lazy and want an instant fix but i want to narrow the options for what to look into and maybe the cause of this frustrating issue.

I recently put a new fuel sending unit because of the infamous fuel leak, any chance it maybe related ?? Or is it the CPS as most of the people say ??

i would really appreciate it any help from you guys, thanks a lot.

JoeJErnst

I'm not sure what you mean by accelerating and braking at the same time, but it reminds me of what the car feels like when trying to race it in limp mode. The engine makes a lot of noise like it's doing a lot of work, but you don't really go anywhere.

Start by borrowing an OBDII scanner from your local auto parts store and see what codes come back and go from there.

Venom55

Thanks for the reply really appreciate it,

Then the best thing to do now is reading the codes, i will update u once i do it.

Thanks

Venom55

So I checked the codes and i had these
P2007-8
P2046
P200B-1
P207E-1

I hope i get any input on these, is there any chance one of them is causing the hiccups ??

bbirdwell

P2007 is the B28 MAP sensor
P2046 O2 sensor signal upstream implausible
P200B-1 Camshaft Hall effect sensor
P207E-1 Catalytic converter efficiency low

My two cents? Start with the MAP sensor, then the camshaft sensor, then look at the O2 sensor and then the cat. If it's the MAP sensor, that will cause all of the other codes.

Dublinoh

Venom55, because you are new to the forum, I just wanted to let you know that information from bbirdwell is some of the most respected and accurate on the forum.

Venom55

I will definitely keep this in mind thanks for the info.

Venom55

Sorry if i wrote a lot and excuse my English.


Thanks for the information really appreciate it. So i took it to my mechanic and he told me that he cleaned the MAP and fixed something in it ( i dont know what he fixed exactly), he also changed the number 4 the coil and the wire after it came with the codes, he also cleaned the injectors.

I took the car after he fixed the stuff and the only thing it got fixed is the shaking when u are in idle maybe it was caused by the misifre of the bad coil, and i was really happy until later when i drove it for a while to see if the real problem is gone, i gave it WOT and damn there was no power like absolutely no power, i thought maybe i didnt press the gas properly (which absolutely ridiculous) but i am trying to make my self feel better because of the money I paid.

Later after 30-40 mins of driving the car i hit WOT again and the same exact problem is there, it is like suddenly someome hit the brake without warning and the car wont move until i remove my foot and hit it again softly very softly and it barely reaxh 30 kilos per hour. !!! I hit it WOT again and the car feels like it is choked if i can say.

I hope I described exactly what i was facing and actually i reas a lot of posts with the same symptoms i am having.

I really really love the car and i want to drive for a long time.

Do u think u have a clearer idea about it now.??

Btw the throttle body was opened and was cleaned.


Thanks for the answer and i hope i get the permanent fix soon.

JoeJErnst

Sounds like it is still going into limp mode. Check for codes again. You probably have a sensor giving bad information to the ECU so it is shutting things down to avoid a catastrophe.

StarvingArtist

You don't clean map sensors, you replace them. Most of what you paid for sounds made up with no way to prove. I'm getting a weird vibe from all that. especially the map sensor thing.

karikuuva

Check your car fuel pressure first In my car have same problem.If it is about 50psi in idle and drops under 40psi when you give more throttle on the road,so that is the reason.Good pumps gives 60-80psi.

bbirdwell

A misfiring cylinder will certainly cause the car to be very down on power; I only had one cylinder out and the car was very slow to accelerate but yours sounds much worse.

As StarvingArtist stated, you replace MAP sensors, you do not clean them. If the MAP sensor faults, the ECU will default to "limp-home" mode and do everything in the program to keep you from blowing up your engine. Don't try to clean the MAP sensor; replace it.

Basic checks now:
-fuel pressure at idle should be 78-82 psi (5.4 -5.6 Bar).
-read codes; a misfiring cylinder will provide the code for the misfiring cylinder. The code is P030x with x=cylinder that is misfiring. i.e. P0301 means cylinder #1 is misfiring. P0302 and P0306 means cylinders 2 and 6 are misfiring.
-the misfire code will also come with a warning "misfire, damages TWC" (three-way catalytic converter)
-it could be as simple as cheap spark plugs with eroded electrodes (that was the cause on my car); or spark plug wires in poor condition.
-I will say it again. If the engine is misfiring, the ECU will throw codes! No ifs, ands, or buts. It will throw codes and it will tell you which cylinders are misfiring. At that time the usual suspects are spark plugs, wires, coils. Far less likely is a wiring harness problem.
-Have you seen the P030x codes yourself?
-Since your car failed accelerating, you will have codes stored. Pull them. If the MAP sensor is there again, replace it.

Venom55

So the news finally came out, it was the freaking fuel pump from the beginning ���� it gave me such a headache even though i should knew it from the beginning because i felt like the car was sucking just pure air sometimes, so any idea about how to make the fuel pump last longer this time ?? I heard that keeping the gas low most of the times will cause damage with time !! Is that true and is there any after market pump or it has only the original amg ?? Sorry if this question a little nit stupid.

Thanks fir all thise who helped me with this issue I really appreciate it guys.

rapidoxidation

The fuel pump depends on fuel to keep it cool. Low/no fuel means the pump gets hot and that can kill it.

Keep more than 1/4 tank of fuel in the tank and drive happy.

bbirdwell

Venom55,
Read this:
https://mbworld.org/forums/w211-amg/...intenance.html

Very important (since I do not know where you are located) that you used the proper adapter cables with the fuel pump and fuel filter. Later model fuel pumps reversed the power/ground connection on one of the two pumps; if you do not have the proper adapter cable, one pump runs backward and fuel pressure is too low.

Thank you for posting the resolution of your car's problem.