Hi I have 1999 sprinter 312d 4x4 UK specification WDB9034612P933743 which I am restoring ( work since November can be seen at.. https://www.facebook.com/Sprinter-4x...2569177218393/ )
I am 1970's mechanic ie. understand nuts n bolts n hammers, struggling to understand engine management especially on 1999 312d with 14 pin diagnostic socket and pre OBD11 (at least I think so).
I have a not very accurate copy of WIS (when I put in vin number it says not reckognised) which sometimes is helpful but not for present problem
I am trying to find out why sometimes the vehicle does James Bond type smoke screen and then other times runs OK.
I do NOT think it is a mechanical (ie. head gasket, rings etc,) problem fairly certain it is engine managment

engine is smoke free at tickover

When in smoking mode and revved the engine surges and vast amount of smoke come out.... when i disconnect the grey "injection advance connector" on the top of the engine (next to the black lead injector/needle lift connector, resistance on lead injector 120ohms) then the engine stops producing smoke and smooths out.

When I connect the vauum pipe directly to the vacuum controller for the turbo charger the white smoke stops.....Problem according to my copy WIS my turbo charger has vacuum controller that is only connected to turbo charger whereas MY engine has vauum contol unit mounted down behind lower heat shielding just under inlet pipe from air filter and the control unit has brown and green wire which as best I can connect volt meter has 6.7 v. ignition on.... I don't know if there is a problem with this unit (or voltage) but if it in vacuum circuit then sometimes I have smoke....

Is there a way of testing this unit?

Pictures are address above

The vacuum pipe which goes to this turbo contol unit is connected to the first T connector of off the white pipe coming of the vacuum pump and going to the Brake servo .... Just after it T's off it goes through filter and splits in 2 one of which has grey stripe and goes to head light adjust.. the other pipe the plain brown does not seem to hold vacuum... connecting vac guage in I get reading of 35"hg on previous part of system but when the brown pipe going behind the heater "box" is connected then vacuum is lost...... there are 4 pipes splitting of behind the heater box one of which goes to turbo charger control...identifying the others difficult without removing heater "box"
.
Can anyone with good WIS bring up document number that I could use in my WIS for (or post diagram/info)
1. engine management etc. vacuum diagram that identifies what the various vacuum pipes sre for
2. test procedure for remote vauum controller for turbocharger

any suggestions or help appreciated. Mark