Sprinter 310D Elusive fault

[sprinternut]

I have a 97 ex Transco 310D (120k Miles),which has an intermittent fault.It has been to an auto electrician,Merc commercial specialists and also an ex Merc master tech diagnostician with no success.

The van will suddenly decelerate on it's own,as if the throttle has been released,but more abruptly.When this happens pressing the throttle has no effect,but dipping the clutch does not stall the engine.The edc light does not come on and this fault is random at any speed/throttle position.The power "outage" can last for less than a second,to about 5 seconds

All parties to check the van have connected it to diagnostics and the ecu does not log a fault.It has been road tested with diagnostics and when the fault occurs,I was told that the fuel pump showed zero?

The conclusions of all parties were to point an accusing finger at the voltair system (PTO driven compressor and generator)To this end I disconnected the control module wiring from the throttle potentiometer (Wiring was poorly done with splices) and the van has been spot on until now (approx 6 weeks)

Any ideas anyone????

 

[wireman]

It could be one single not too well made electrical conection, there's loads of them and finding it will take time.
Try to individualy inspect the wire to crimp on all wires in the harness which have any association with the engine management pay carefull attention to the pins in multi way connectors i.e. are they making good contact when installed in their appropriate connectors. I have found wires with insufficient insulation striped off them crimped in and then showing occasional faulty behavior as the conection gets broken and remade on several occasions.

 

[technical01]

brake light switch?