nissan bluebird 1994 automatic

1994 Nissan Bluebirdi have had to replace the rocket gasket seals.
ive put in new spark plugs
ive put in injector cleaner.
and when car is parked up and the hood is up there is an air leak somewhere.!!!
but my car still jerks a little but when driving!!!!!!!!
its starting to frustrate me


You will need to start with pulling any check engine light codes. Post the codes below in the comments. Find and repairing the vacuum leak would be a good thing as well. You may find it shows an engine misfire code. The first place to check would be an intake gasket for a vacuum leak.