caddy bukkie cutting out problem

[Garymac]

hi my caddy bukkie is a 2006 model with the round dash . At any it would just cut out this is a ignition cut out because the engine just cut the tacko drops to 0 even if the engine is still turning because i have not pushed in the clutch but the speedo ,fuel and temp guages are still showing normal , the oil light comes on and the busser busses , turning off the igntion and on again does not help when slowing down even removing the key and putting it back in when still costing does not work cranking the engine also no help .
BUT if i pull the distibutor black 3 pin plug out and plug it back in then the engine fire up immediately .
I have replaced distributor and 3 pin plug with new ones
replaces the coil
replaced both engine and cluster computers
replaced ignition key switch
All been replaced at vw agents
cleaned the engine bay eath conections
no failures are showen when vw does diagnostics on it
Stil the bukkie will cut out at any time all i do is plug out the 3 pin distributor black plug and plug it in and the engine fires agian

this problem is getting verry frustrating

[PapaJo]

Sounds like you have a bad or missing earth wire on the wiring harness.

[Garymac]

The earth connection in the engine bay have all been cleaned but someone did mention that there are earth connection under the dash but the dash will have to be removed to get to them can some confirm if this is true

[PapaJo]

If you remove the bottom halves of the dash, you will find earth points behind the cubbyhole towards the internal fan box side and then also on the support bracket below the steering column.

[Garymac]

report back on an old problem that is still there .
Have cleaned all earth connections even the 2 earths under the dash , soldered all lug to wire connection + and - cables , replaced the 2 big fuses next to the battery but the problem is still there .
Any ideas would help because i am now

[PapaJo]

Did you check the power feed into the fuse box?
Do you have an immobiliser installed?

[Garymac]

Checked the fuse box had the engine running pulled out and replaced one fuse at a time , only fuse that made the engine cut is the over run cut of valve on the carb fuse but it only cuts the engine when in idle has no affect on engine over 2000rpm . No othere fuse made the engine cut out so can't be fuse box .
There is no alarm only the vw standard key chip immobilizer

At times the engine will cut 2 km from home othere time I can ride 25km to town and around town and only on my why home it would cut out some times it would and and come rite othere times it would back fire with sudden jurcks .
The times it did cut and I had to stop, all I do is unplug the distributor 3 pun plug out and in and it start again but I have replace the distibutor and black 3 pin plug and wires with no inprovment .
Coils been replace and the 2 black control boxes under the dash .

I can pull around on the wire harness under the dash and in the engine bay when the engine is running with no affect so cant se there being problem with the harness

[PapaJo]

Any repairs being done to the wiring harnass at some point of its life?

[Garymac]

Can't say bought it second hand , so could be, can't see any new wires all the plugs are standered vw plugs apart from the new 3 pin plug i installed in the distibutor and the wire harness is on it place