ford fiesta 1.3 wont start help please we have tryed everything

[kirstame]

my ford fiesta 1.3 1995 n reg will not start.
about 2months ago the car was running, but occationally when u accelerated in gear the revs would lower dramaticlly, and most of the time that would cause it to stall. then one day it just stoped starting, it turns over but wont fire.

we can get it to fire up when petrol is put in the top of the carb, but it stalls as soon as that runs out. we have replased all electrial sensors, management system, fuel filter. spark plugs, spark leads, air filters, oil, carb, checked the fuel cutt off switch and thasts fine. fuel pressure is fine, and there is no problem with key coding.

and now after 2 months of trying to get it started we have no more ideas what it could be.please please please help.

Kirstame