W124 300ce Cutting Out (again!)

[ducati]

J reg 300CE 24V hesitates/runs rough for a few seconds then engine dies - may start again on idle but cuts out on any acceleration or wont start at all. Feels like it has run out of petrol. Leave it for 30 mins (or until RAC arrive) starts and runs perfectly until the next time which may be days/weeks away but it is happening much more often now.

? fuel pump relay - where is this? is it the one behind the battery with a fuse on top (or is this the VPO) or is it with the other relays.

Someone said check the voltage across the fuel pump - there should only be voltage when the engine is running hence the relay (except for when you first turn the key on star-up) - if I check when the engine is running then it will be OK, if I check when it has cut out there will be no volts as the engine is not running so I don't see how this helps.

Any other suggestions - can relays intermittently fail?

Thanks

 

[evo-number-one]

I had same sort of problem with my Integrale.

Could be the Crank position sensor.



Bob
e-n-o

 

[ducati]

Someone must know

Come on! Everyone goes on about the fuel pump relay but I can't find out which one it is!

 

[turnipsock]

I think it's either behind the battery somewhere or near the offside rear wheel. (it depends on the model)

Relays provide a way of switching large currents, therefore the contacts become pitted and burnt so they eventually fail.

The easy way to test it is replace it with a new one. Once you have the new one, you will be able to identify the location of the current one.

 

[C220GJS]

Try this link ; http://www.detali.ru/cat/oem_mb0.asp?TP=1.
Find your car 124.061 I think, then sections 54 > 040 > item105 is the fuel pump relay part no. 0035452405. Don't know the location but the diagram may give you an idea , seems to be in the engine bay next to the OVP relay.
Geo.

 

[ducati]

Many thanks - not the clearest diagram in the world though!

 

[Smalltar The Impaler]

Sorry to ressurect an old thread, but did you find out what the problem was? I have almost the same problem with my car.