Renault 5 gt turbo slight stutter before revs...

[rumpelstiltskin]

Restoring a little Renault 5 gt turbo phase 1,1.4 turbo petrol carburettor engine(For those that don't know)It's a Solex 32 DIS something or other carb,from memory.Anyway,i'm starting her up regularly during the resto and when it's idling it's perfect,choke everything working bang on.It's just the second you take up the strain on the accelerator there's a slight hesitation/stutter then it revs free all the way up cleanly,it's always right at the start of the touching the accelerator,no miss anywhere else?I noticed a fuel leak at the accelerator pump diaphragm housing,put new diaphragm in thinking maybe that would solve it but no,carb has a new mixture screw only apart from this. There is a small L shaped downpipe that comes off the turbo then goes down,that join is leak free,but where it joins onto the rest of the system there is a slight blow,would that cause this?i intend in future to rebuild carb but run it in the meantime,anyone any ideas?Cheers!