My mittsubi mity max has a startering prob

it willnot do anything when i turn the key well sometimes it starts but most of the times it just sits there

i removed it took it to the shop thay bench tested of course it worked fine

put it back in an it korked for two days then no work no click no noughting

i tryed jumping the silionid still nothing

i let it sit for three days went an it started fine

for once shut it off an once again on go

is the silionad bat should i replace the entire starter