I think i'm going to go with rebuilding the carbs!!
With the use of my new gauge i,ve ran the electric fuel pump from 1.5psi - 5 psi (thanks Greg) and its made no difference. She's obviously running way to rich as you can smell it, the inside of the tailpipes especially the right bank is very black and the plugs are black. The carbs are the only thing I never rebuild other then checking the float levels.
Pascs: I'll be using ITG filters when they arrive. Its somethink to think about in the long run but at the moment i've not been driving far enough to get any major heat build up in the engine bay. The engine lid spends most of its time up any way. I had an engineer make up the adaptor plate, new lengthed input shaft and spacer for the thrust bearing. There's a company called Kennedy Engineering in the US who now make adaptor kits to fit virtually anything onto a VW box.
Hoygard: Tried this but no success. Borrowed a cool little gadget to test the module itself and thats fine.
rgwm: What distance i've driven everything seems pretty good. You can't throw her into corners quite like an original imp (but then what can you!!!). Its more slow in and power out, the back end steps out depending on how much power you give her but in a way you can predict. With the running problems i'm having i'll have to get back to you with a full 'on the limits' road test!
Bal2: It should work with my electric fuel pump as I can change the psi from nothing to crazy amounts. I don't have to use it but its one less thing for the engine to drive and I think they look cool!!
Any ideas on were best to get carb rebuild kits from? I've tried Demon Tweeks and Rally Design which haven't got any. Hoopers of Bristol have but here's a long wait for them.
Going to sit in the sun now and look at my IMP. She will not beat me........