Mercedes 300 SE 1988 electrical problem help?!!

[kristo]

Hello all,

I am posting this message on behalf of my father who is having an issue with the above Merc. Hope you can help!!

The issues are:

1. The car starts fine but after a mile or so or once warm it would cut out and would not restart until it was cold again.
This issue was eventually traced to a distributor cap which was replaced along with a rotor arm.
Initially this appeared to cure the problem but subsequently when it is stationary at traffic etc the engine will cut out but now will immediately restart??

2. Warning lights will come on. The fuel light will come on for no reason. The economy needle acts in 'reverse'.

This appears to be everything but can the problems be expected to get worse??

It has not been to Mercedes for diagnosis (due to cost reasons!) but everyone who has looked at it has suggested that it is something that it has not been.
There has been a suggestion that the issue may be with the onboard computer system???

Any suggestions would be appreciated.

Kris

 

[jaymanek]

No such thing as on board computer system..

The economy guage is just a vacuum line from the engine, if its working, its got to be working correctly.
Fuel light will be due to sender being faulty I should think.

The 300 engine does have a problem with moisture getting into the caps, this is probably still the case..
cutting out could be various things from OVP relay to fuel distributor to just needing a good old tune up.

 

[m7m]

I don't know if this will help.
I have a similar car which developed few electrical problems shortly after taking it to the MB dealer to fix an unrealted mechanical problem. The reason for the electrical faults did not seem obvious. The result was a full discharge of the battery. So, I took it out and charged it, then everything started working correctly. The only explanation I can think of is the removal of the power from the on-board computer, erased the information in the temporary memory (RAM). i.e. everything is reset. :bannana:

 

[jaymanek]

The only explanation I can think of is the removal of the power from the on-board computer, erased the information in the temporary memory (RAM). i.e. everything is reset. :bannana:

we are talking of a car developed in the 70's here!

 

[BlackC55]

I would be thinking OVP relay or fuel pump relay as a good place to start.