2005 2.5 xtrail

2005 nissan x trail just bought it. Started it ran beautifully. Took it home. Second day ruff and hard srart. Second day idle really ruff and hard start. 2.5 did a little resurch replaced the crank senser. Bob's your uncle off the races. Next morning fan belt flew off. Replaced it. Next day coming home darn thing starts bucking sitting sputtering heat gage Flys to the over heat I shut it off check the fluids all where they should be. Restart but has an issue tring to idle. Try to give it gas it reves up to 2000 rmp then cuts out reves up cuts out. When in drive you can gradually climb up to 80 ks an hour then bucks like crazy. If slightly holding the fuel pedal try to increase pressure on the fuel it bucks ? Any help me with this ?