W124 cuts off while driving

[sub_zero]

Hi all,
I have a w124 E220 95 ,sometimes while driving the car cuts off and I barely go aside to let others pass,when I try to start again,it won't start,if I wait for a couple of minutes,it will start again.
this is not usual,but in suddens that I'm totaly losing confidence driving the car,while am on high ways or crossing junctions,I pray for God to pass without cut off.
I have changed the Fuel pump recently,I bought Bosch fuel pump,though it is not OEM.What could it be? I'm totaly frustrated and helpless,no good technician to help me here (am in Kuwait).
Thanks in advance
trying to be proud owner

 

[Will]

Worth checking the fuel pump relay?

Will

 

[grober]

Fuel pump relay as has been said or possibly the OVP (overvoltage protection )relay Both can found behind the flexible black plastic cover behind the battery.They can sometimes be repaired by opening up and resoldering connections with a soldering iron http://mbclub.co.uk/forums/showthread.php?t=21597 but probably best replaced.

 

[bolide]

Could be the AFM. I've experience of this affecting 220s

Nick Froome
www.w124.co.uk

 

[sub_zero]

changed the fuel pumpr relay

I have replaced the fuel pump relay ,and still facing the same problem.
I wonder,sometimes the car is working fine,going everywhere without cut off!!!!
didn't replace the OVP (over votage protector),how would I know it is the guilty part?

 

[Howard]

I had this problem in the summer here, we worked it out it was a vapour lock , i think ..... or a loose vacuum hose ....

As it's much hotter in Kuwait , i wonder if you could be experiencing the same thing.....

OVP relays are less than £50 , worth changing as a start .....

If you can borrow one from a car that you know is ok , you could swap it over and see ....

http://www.mbclub.co.uk/forums/showthread.php?t=28165&highlight=vapour+lock

 

[sub_zero]

could it be the 'crankshaft sensor'?

I have doubts also about 'crankshaft sensor'.what do u think?

 

[Dieselman]

Could well be. The symptoms sound right.

If you can get he car to do it try checking for a spark or lack of fuel at the roadside.
For the spark pull an HT lead and insert a spare spark plug and hold it against the engine and turn over.
For fuel pour a small amount down the intake and see if it fires up.

I think you might well be correct with the CKP but also worth checking the fuel tank breather is working and the earth connection to the fuel pump.

As others have said the OVP would be a prime suspect also.

You could rig an indicator lamp up to the fuel pump connections to display if the electrical supply dies.

 

[sub_zero]

The problem persists

Hi All,
yesterday was a very good day,I went for long journies (of course not for testing the car ) and the car was fine,no cut offs ,but I noticed something,sometimes when I switch on the car,the engine vibrates very odd,this vibration does not go,and while driving the car cuts off,and sometimes when I switch on the engine,there is no vibration and there is no cut offs.I think the MAS is the guilty as I read a thread here about cleaning your MAS,I cleaned it (may be 3 months ago),when I plugged it again I didn't plug it very well (I think),when I started the engine the engine started with vibration,I switched it off and plugged it very well (it has a rotating plug),still the vibration there,so I went to a nearby workshop,they diagnosised it and told me,we reset your MAS,something is wrong with it (I didn't mention that I unplugged it),the car was fine after that.
I want to thank Dieselman for such information,this is my first time to hear about fuel tank breather and earth connection of fuel pump,but I don't see myself capable of making the testing you told me,I think I'm DIY level 1,I don't know where the intake is ,where the fuel tank breather is,or even unplug the sparkers.
I heard there are good condition MAS with 1/3 the price of the OEM MAS,what do you recommend?

 

[grober]

Try this thread http://mbclub.co.uk/forums/showthread.php?t=25262&highlight=mas+replacement

 

[television]

The crankshaft sensor can give all of the problems that you have, we have had many failing in the last few weeks.

Malcolm

 

[Big Phil]

I have replaced the fuel pump relay ,and still facing the same problem.
I wonder,sometimes the car is working fine,going everywhere without cut off!!!!
didn't replace the OVP (over votage protector),how would I know it is the guilty part?

I had similar prob in my 124 300 coupe - engine would cut-out suddenly, usually under acceleration from pulling away, but occasionally at speed. One time i lost all power including power steering and careered across the road onto the opposite pavement . RAC towed me to a local indie who replaced the distributor cap and rotor arm. Problem solved completely, car ran much more smoothly and didn't cut out again.

May or may not solve your problem, but might be worth a look?

 

[sub_zero]

some colleague told me that he suffered the same problem (he had a Dodge)and it was the main computer (CU),is that possible? This would be really bad news for me.

 

[grober]

Possible but unlikely. Would eliminate other possible problems which have been suggested first. Your car doesnt have a distributor but ignition is provided by the ECU TRIGGERING 2 coils each feeding 2 sparkplugs. These coils or their associated wiring have been known to fail causing the car to run on only 2 cylinders which might fit the symptoms you described. Eventually this will cause the ouput driver circuits of the ECU to the coils to fail. There are specialist companies who will repair ECUs http://www.bba-reman.com/
but best to try replacing the coils first after you have taken a careful look at their associated wiring for poor connections / insulation breakdown.

 

[Vlad]

From the symptoms you describe I would put money on it being the OVP Relay....exactly the same happened to me on a C280 and a W124 280

 

[Ian B Walker]

if its a 111 engine look at the fuel rail. At the front of it is a valve with a pipe going from it to the inlet manifold. This valve can cause the problems you mention. (I forget what it is called)

 

[sub_zero]

At last

Hi all,
At last I discovered what was wrong.
I went to a technician last thursday ,he unplugged the OVP,opened it with a screw driver and soldered it,he plugeed it again and we swtiched the car for about an hour with no cut offs.
since thursday and am driving the car with no cut offs (God forbid).
I was thinking of writing to you but I decided to give the car more time to make sure it is the OVP.
I want to thank you all pals,it has been great pleasure joining this group.
Vlad,you were right,it was the OVP.
I'am thinking of replacing the OVP,as it is just soldered,what do you think?
I have posted my gallery at the member's gallery ,I couldn't upload any pics,so I just added some links.

 

[Howard]

Glad you got it sorted Sub Zero .....

OVP relays are less than £50 , i keep one in my drawer now as a spare....

Although the failure is caused by dry joints, so if it's been resoldered it should be more or less as good as new !

 

[grober]

Fixed

Result

 

[Dieselman]

Glad you got it sorted Sub Zero .....

OVP relays are less than £50 , i keep one in my drawer now as a spare....

Although the failure is caused by dry joints, so if it's been resoldered it should be more or less as good as new !

Probably better than new. It's the dry joints that overheat that cause the problem.