Hello friends, I have a 1.3 mpi fiat dune to which I made a change of hoops, timing belt, crankshaft and cylinder cover with valve seats. The issue is that now the car starts but only takes four or five seconds and stops as if it cut the power. The car only goes on gas does not have the gasoline pump

Thank you friend, I inform you that I already found that the failures were a cable that goes to the computer cut the broken spark plugs and several air leaks in the hoses. the issue is that the car is only gas and now when it is heated it accelerates what can it be?