Hi all I've just had my 2wd sapphire live mapped at Norris motorsport . driving back it was 100% a week or so later I took it out and as soon as I hit the boost the turbo in 1st 2nd sometimes 3rd gear the car accelerates then dives forward as if you turn the ignition off and then comes back on if you try to drive tough it just kangaroos violently , its not a misfire as 4th and 5th are fine .
as I had an aftermarket petrol tank on the car to run it in and understood that the metal swirl pot type aftermarket tanks suffer from surging . I got hold a genuine group n Cosworth rally tank and fitted it , took it out and its still the same. I filled the tank too the brim which would top any surging issues from low level fuel pickup issues, Id think its the tank but I have now tried two different tanks ,
its almost like pulling off the map sensor vacuum hose briefly and putting it back on the car just dies . its only on hard acceleration if you drive slowly through second gear it does not do it ,

has anyone got any ideas what to check, its got new plugs , checked all hoses , the map sensor has own feed from the inlet separate from the boost gauge .checked all connections , its a nloom and sensors only done 1000 miles


help please