B2600i Starting Problem .... HELP !

Hey All, My mates got a 2000 model B2600 with the mazda G6 injected motor....

ok so when you go to start it, it turns over but wont fire .... i've checked air, spark and fuel .... air is fine ... i checked for spark and the pulgs were rusted over so we replaced them still nothing .... i checked for fuel and when i pulled the return line to the injector rail it kicked over ..... but went back the next day and it wont start now .....

any ideas ? im thinking maybe a blocked fuel filter ? or could it be a relay or fuse ?

any help would b great .... thanks in advance

Did you check for spark at the coil? Or try starting fluid, if it starts with that then it is indeed a fuel related issue in which case id test the fuel pump relay and the pump itself and replace the filter (especially if it hasn't been replace in a while)