E55 suddenly cutting out.

[icarus51]

Hi guys,
This could be a long description, but I want to get all the info out there. I have a 2003 model with 216K miles on it. About 5 years ago l had it remapped and a smaller supercharger pulley fitted. Everything has been fine until around 6 months ago. I was having a "spirited" drive when I came up behind something and needed to overtake it. Travelling at about 40mph i pulled out and pressed the throttle pedal down a fair way but not as far as the kick down switch. The gearbox appeared to drop a couple of gears and then instead of impressive acceleration, it was if I had turned the engine off, or fuel had been instantly cut off. I shot forward in my seat only for the car to then complete the gear change and accelerate away as I expected. Prior to this, with"normal" driving the gear changes were fine and predictable. I tried another rapid overtake and everything worked as it should. Therein lies the problem, it is so random. Guaranteed it'll do it at least once every time it's taken out, but you get no warning when it decides to cut out. IveI had the gearbox serviced and the conductor plate replaced, no difference. No warning lights and my indy has said no stored faults. Has anyone had anything like this happen to them, or does anyone know the cause and how to fix it. At the moment I'm very wary of overtaking anything due to the violent nature of the cutting out and the stresses potentially being put on the gearbox. Any ideas anyone?

 

[Deleted member 37751]

Sounds like the infamous CPS failure - if it is that, it will start doing it more often.

 

[Will]

Doesn’t sound like a CPS to me? They usually cut the engine out dead and won’t restart until it has cooled. Usually stores fault codes too for no crank sensor readings.

 

[Dogbreath]

Ic pump

 

[Abb]

+1 For the IC pump

 

[andy27168]

Another here for the IC Pump.

 

[AMGeed]

+1 IC Pump.

 

[icarus51]

Thanks for all the replies. I had an uprated Bosch 010 pump fitted about a year ago. I would hate to think its worn out already. What makes me wonder if it is the pump is that immediately after the hiccup the car will quite happily accelerate on WOT with no loss of power at all. Could it be related to the map update? Seems strange that it's only happening now, years after it was installed. I look forward to reading more thoughts from the forum.

 

[Lenny63]

Try rebleeding it?

 

[Gbrowncls55]

If the ic pump fails does it cut the engine totally or just dissengage the supercharger? I thought it was the latter

 

[merc85]

Old thread , it cuts the S/c out so just go’s like a normal 5lt v8 lol

 

[ChrisHampshire]

Intermittent problem with the fuel pump?

 

[whitenemesis]

From WIS -
The compressor is also not actuated when the battery voltage falls
below 9 V or when an error is recognized in the charge air cooling
system due to an implausible value from the temperature sensor

 

[merc85]

Intermittent problem with the fuel pump?

could be although when mine played up it was ever time when the engine was hot and at wot. Ended up replacing with twin Walbro pumps

 

[icarus51]

Hi all,
Again thanks for the replies. I wondered about the fuel pump. The symptoms are all most identical to when I owned a tuned Saab 9000 Aero. If I floored that, occasionally i would hit the overboost switch which cut the fuel pump. It was like hitting a brick wall. When I floor the amg it feels exactly the same, problem is it's not repeatable. Sometimes it does it other times it behaves normally and takes off like a scalded cat. It's so frustrating and makes me reluctant to drive the car, the jolt which is caused has me worrying about the stresses going through the gearbox. Hopefully someone on the forum will identify exactly what the problem is.
Cheers all.

 

[Dogbreath]

Have you had it on Star ? Surely it must throw a code when the problem is happening ? Maybe worth a try

 

[icarus51]

This is where the problem lies. My indy has put it on a star machine and no codes are listed.

 

[ChrisHampshire]

FWIW, on my W220 the fuel pump failed completely (car wouldn't start) and no codes were logged.

 

[merc85]

No wen the Sc cuts out it’s not like Turbo boost cut out at all. I reckon as said fuel pumps are getting weak wen there worked hard. Your better off changing them singly as Mb only sell the housing which has been updated so you have to buy the sendor too in the other side of the tank roughly £1,200 for both. I uprated mine with twin walbros and a new filter housing.