scoobywho

Picked up an 88 2wd saff 2 weeks ago thats been sat for 3 years, greens,rs500 intercooler etc,it starts and idles spot on.Unstuck the brakes and thought id copped a good'un,changed anti freeze,cleaned plugs,all good.Started it five or six times since then and let it warm up to temp.On Monday, started it again and all was well then it cut out and wouldnt start,eventually started 2 hours later and did the same again,bit of research later suspected cts,replaced with genuine weber one,fired straight up and no probs after that,booked in for mot today,went to set off to mot and the bitch started then cut out straight away and wont start at all,all earths are good,new leads.pump primes and all seems in order,volts are right at alternator and pump,nothing is clicking when it shouldnt be,£35 of the good stuff in the tank too,i had to walk away till tomorrow,ive got genuine brand new crank/phase sensor to fit but the fact that theres no misfire when it does run and revs properly when asked to has got me stumped,any ideas much appreciated and thanks in advance