Cheers Benny.....I totally agree with your diagnoses rationale. It struggles with both scenarios really. A quick blip in neutral will definitely stumble/gasp for fuel (clearly shown on A/F guage), however quickly repeated subsequent blips will tend to be smooth. It feels/seems like the liquid fuel from initial throttle opening is just used to line runner walls to allow fuel from subsequent throttle movements to easily flow into cylinder. So increasing fuel delivery from accelerator pump may help, but I can't help feel that it isn't the whole problem. I'll certainly look into the pump, but I know it's working pretty well. Perhaps it could deliver a little quicker though. It's worth noting that pulling away from a stop or from reasonably low down in any gear will hesitate as well (also shown clearly on A/F guage), and this is generally only a gentle accelerator movement, relying more on the progression curcuit than acc. pump.

Haven't removed bridge in manifold.....

Thanks for all your help again.....Stu