phase sensor / engine trouble - Help!!!!!

[ben]

got problem with 98 hgt - when engine is hot car wont restart if turned off. had phase sensor replaced as this came up on diagnostic check - ran fine for a week but problem has now reoccured - had another diagnostic check and same reading showing - phase sensor and rpm sensor?? i now f*'k all about cars anyone had this problem? can i get it fixed cheaply? Taken it to garage who reckon £750+ to repair as engine needs to be taken out to replace part,new cam belt as engine coming out and loadsa labour!!!
Geezer not familiar with fiats can anyone help??

 

[Tom]

The cam sensor (phase sensor) is behind the cam drive wheels, cambelt off job.

I seriously doubt they changed it the first time.