Old fiesta engine swap

[Adrian112]

Hello everyone.i m having a bit of a problem with my dad's old fiesta.it s from 1996.the original engine had it s last breath (zetec 1.25 cc ,75 hp) and I did an engine swap.Old engine was a dhc ,new one is dha.the " new" engine starts smooth,rev' s ok but if I drive it a bit more aggressive starts to shake for a little bit and the top speed isn't even close to what it was with the first one(120 km vs 185 ) .I didn't changed the ecu because I couldn't find an engine with ecu.Could that be the issue?all the 1.25 cc engines have the same hp, everything is identical,except the last letter from the engine code.thank you in advance