W124 E320 Estate `94 *Intermittant cut out*

[Richydev]

Engine intermittant `cut out`. HELP. Not had the car long, my mechanic is stumped ? Starts and runs beautifully, then after stopping (at traffic lights / junction), just cuts out ?? Nothing obvious, checked all the forum threads, but can`t see one to match. Other days it wont do it. Usually after/during short journey. Once it cut out whilst I was driving. It used to start again after 5 minutes or so, but the last time, it wouldn`t start at all for days. When it happens, turns over fine, but no fire up. Could this be electronic / fuel cut out / Now it is with mechanic and starts all the time !!! typical. What do I check ? he cannot find any faults......Please help.

 

[trapperjohn]

Sounds like "crank position sensor" or perhaps fuel pump relay. But that is an armchair mechanic talking. Others with proper qualifications will be along soon.

At least my comment will "bump" your question to the top of the threads for now

 

[abecketts]

has the engine wiring loom been changed on the car, check the forum for a "sticky" thread on this a known fault on these vehicles though John maybe more in the zone in your case.

Welcome to the forum

 

[BlackC55]

I doubt a CPS issue but you never know. I have never changed on eon a 104 engine and they are generally very reliable.

Listen when it does it again and see if you can here the fuel pumps prime atthe rear of the car. If they dont suspect the fuel pump relay.

OPen the wiring loom up too and see what state it is in.

 

[GP801]

Had a similar issue on our 280 last year. As above check if the fuel pump is running. It was the OVP relay om ours rather than the fuel pump relay but ended up doing both just to be sure.

 

[haaran]

Had similar symptoms on a 300-24v. It turned out to be the Ignition Control Module.

 

[bolide]

Had similar symptoms on a 300-24v. It turned out to be the Ignition Control Module.

In lots of ways the 300-24 is a different car. There is no ICM on a late M104 (E280 / E320)

I'd plump for fuel pump relay or OVP. Or even the MAF

Nick Froome
the independent Mercedes Estate specialists

 

[kth286]

Richydev

Is you mechanic experienced on this generation of Merc.

If not take it to someone that is.

Let us know where you located and you will get some suggestions.

the fault codes need to be read - has this been done and what codes were present, if any ?

 

[Richydev]

Richydev

Is you mechanic experienced on this generation of Merc.

If not take it to someone that is.

Let us know where you located and you will get some suggestions.

the fault codes need to be read - has this been done and what codes were present, if any ?

Thanks for all the suggestions. I work overseas so just got back and mechanic says that he couldn`t get a Fuel pump relay ANYWHERE. I made a couple of calls and sourced two in stock straight away. Took the car back home in disgust.
Fault codes...well I`ve been told that although this car has an ECU it does not have a "fault logger", so you can`t see what`s happened, until it actually happens !! The mechanic told me that he has started her up lovely every morning no probs, however, when I turned up, it wouldn`t !!
Another mechanic that I know said that FPR`s can easily be `cleaned out`, so not usually that. Crank Shaft Sensor is heat related, i.e. when they get hot, they can cause engine to cut out, well don`t think it`s that either as it was stone cold a couple of times when it happened !!
OK so you`ve given me some other options now....Ignition Control Module ?? and OVP relay (whatever that is ?), and a MAF (not a clue what that is).
I live in Newton Abbot, Devon. I need an expert to take good care of her as I am desparate to get rid of my Audi Allroad and drive my dream car Merc. Always wanted one, now I`ve got her and nobody in this area knows what they are talking about.
You guys are great.....
Nick Froome....(independant Merc Est Specialist) - where are you based ?

 

[Richydev]

Wherever it is that I take her, she could do with a service and there is perhaps a very very faint knock on speed ramps, but most people wouldn`t hear it (front right), but bit of a perfectionist I am......

Oh, and when I got it back, the square plastic hollow housing in the back seat where the seat belt is retained when not in use, was shattered to pieces, so I need a new one !! can you still get these ??

Appreciate all your help guys, love this club, but am overseas working a lot, so do what I can when I home. Just need to hand to someone good and reliable (specialist) to sort.

Thanks, Richard.

 

[GP801]

OVP relay sits behind battery. It has a fuse on top. It is involved in lots of functions including the fuel pump. We had the intermittent starting problem on ours. It was the OVP relay - £65 from MB dealer. We also changed fuel pump relay. No more probs since.
Dont know a specialist in Devon but I really rate Olly at PCS in Horndean. He transformed our 124 such that it now feels like a new car. Well worth a journey to see him.

 

[Terry_]

Don't know what the tech means when he says you can't read codes. You can read all codes with star on your car. Someone with experience will diagnose your problem pretty swiftly

 

[millo777]

Not really adding anything that hasn't already been said, but I would also suspect the fuel pump relay.

I've had 2 Volvo 760's of the same era and experienced exactly the symptoms you describe, which turned out to be bad solder joints in the fuel pump relay. After replacing one of the relays I took the old one apart and it was clearly visble where the solder would expand slighty in operation just enough to break the circuit connection, then after 15-30 mins it would contract enough to make the circuit and the car would then re start. fwiw, they were bosch branded relays as well. They were actually repairable by replacing the offending solder joint.

 

[grober]

Thanks for all the suggestions. I work overseas so just got back and mechanic says that he couldn`t get a Fuel pump relay ANYWHERE. I made a couple of calls and sourced two in stock straight away. Took the car back home in disgust.
Fault codes...well I`ve been told that although this car has an ECU it does not have a "fault logger", so you can`t see what`s happened, until it actually happens !! The mechanic told me that he has started her up lovely every morning no probs, however, when I turned up, it wouldn`t !!
Another mechanic that I know said that FPR`s can easily be `cleaned out`, so not usually that. Crank Shaft Sensor is heat related, i.e. when they get hot, they can cause engine to cut out, well don`t think it`s that either as it was stone cold a couple of times when it happened !!
OK so you`ve given me some other options now....Ignition Control Module ?? and OVP relay (whatever that is ?), and a MAF (not a clue what that is).
I live in Newton Abbot, Devon. I need an expert to take good care of her as I am desparate to get rid of my Audi Allroad and drive my dream car Merc. Always wanted one, now I`ve got her and nobody in this area knows what they are talking about.
You guys are great.....
Nick Froome....(independant Merc Est Specialist) - where are you based ?

As Bolide said there is no IGNITION CONTROL MODULE on your later model both fuelling and ignition are controlled via the engine ECU.
The fuel pump and OVP relays can often be repaired by removing the covering can and then resoldering [ basically remelting the solder] on ALL the joints on the small internal circuit board with a small electronic soldering bolt.