Old girl Mercedes 280E start stop

[spartan]

Hoping some wise person on here can help get my old girl back on the road. For some reason when I start her she runs for approx 3 mins then just cuts out, as though you have turned the key off, the more times you start it the shorter the running time is. I have checked loose wires anywhere replaced the coil checked the fuel is being pumped even when stopped checked the leads and distributer when it runs its perfect not missing a beat and when it stops it does just that no burbles or anything. As far as I am aware its fitted with the bosch k tronic . Its a 1983 on a A plate, has the 2746cc engine petrol automatic. Really hope someone is able to give me some advice cause a visit to the garage is not affordable as I said she is a old girl and not worth a lot of money.
Kev

 

[pascal]

If you put the word OVP into the search at the top of the page, you will get lots of problems answered on engines cutting out, stalling etc.

PS. Welcome to the forums

 

[spartan]

A bit more info

Forgot to say when you restart it starts first turn of the key no misfires or anything.

 

[pascal]

Yea, loads of possible solutions to that also.

The reason I say to do a search with 'OVP', is that almost every time a problem like yours occurs, OVP relays are mentioned somewhere in the text as a possible solution.
But there is lots of other solutions, like injectors in these threads.

 

[spartan]

Thanks pascal for that already tried trawling through all the postings gave up with a bad head but your suggestion gave me loads of possible solutions thanks very much you know what I will be doing tomorrow now then.
cheers kev

 

[pascal]

No prob, read some of them myself, but most boil down to three or four solutions in total. Start by reading some of the ones with 5-10 posts, they usually have a conclusion.

Pascal

 

[spartan]

I have spent the day trying all the suggestions but to no avail what I would really appreciate some advice on is there any cut off relays that I need to check, its fitted with the k-tronic ignition 1983 w123 2746cc automatic petrol. Where a lot of suggestions on other threads is to check the relay hidden behind the battery mine has nothing like this so any help would be more than welcome easter bank holiday without my lady does not seem right my main cars an escort so do you blame me.
kev

 

[guydewdney]

i would definately look at the igintion amplifier on the left side wing - they are known to go belly up - usually because of bad earths (so worth cleaning the back of it and putting in new screws - simple, very cheap and easy / clean...


so does it re start IMMEDIATELY? or do you have to leave it for a minute?

 

[pascal]

Spartan, When you take it out for a drive, is it ok?

My old 300ce used when letting my foot off the trottle slowing down going into roundabouts etc. Re-Started first time every time, exact same as you describe.

I put injector cleaner in the fuel, and it was fine after I used up the tank of fuel (cut out a few times whilst cleaning).
Never cut out again till its demise a year later.

I would also re-check the distributer cap/rotar

 

[spartan]

It starts immediately no hesitation no misfires seems as though its the ignition but I directly wired it to miss out the ignition switch and it still cuts out you can still hear the petrol pump going for a few seconds after it stops. so it doesnt seem to be a fuel problem. Will try the earth contacts . I have fitted new coil cleaned the dibby really got my head scratching . Advice more than welcome thankyou.

 

[spartan]

Hi Pascal can no longer take it for a run does not run long enough to reverse it out my garage. But when it first started to do it a few days ago you could resart it whether hot or cold straight away slowly getting worse. I will not have her put down. lol

 

[webby]

Hi Spartan,

This sounds like the same problem I had with a Saab 900i a few years ago....fitted with a Bosch J tronic system it turned out to be the fuel pump. The bearings in the pump were worn so it would start each time but after a few minutes the pump would seize and then the engine would stop.
The confusing thing was when you measured the fuel pressure and quantity all seemed normal....took forever to find.
The other thing is the fuel pressure sensor, I think your car is fitted with one, it might be an idea to by pass this and see what happens.....I did this on an old BMW 520i before and it seemed to cure the problem.

Just a few thoughts

Good Luck

Webby

 

[njpumphrey]

It does sound like a fuel delivery problem. If you can hear the fuel pump it is probably not the electronics, but it could be the pump bearings or some blockage in the filter or the fuel line? Would it be worth diverting the fuel line to a bucket and bridging the fuel pump relay (in the passenger footwell - pins 87 an 35) to see if it can maintain a steady flow?

 

[spartan]

Hmmmm might have a point there I presumed that because you can hear the pump it was working. Altough the last fuel problem I had with a Passat as the engine cut it coughed a few times before stopping, this just cuts out.
thanks again will have a look at the pump to see, this is now becoming a battle of wills think the mercs going to win.
Kev

 

[Wafter]

Hi
Just a thought. Could it be the fuel filler cap not allowing air in and therefore causing a vacuum and therefore fuel starvation? Might be worth trying with the filler cap removed.
Alan

 

[spartan]

Not tried that Wafter . Fire in superstore carpark may be the answer sorry may be a sore point for you but I am really getting temted to cremate it.