are fuil injecters tight when installed.

If the fuel rail is tightened down and the injectors can be moved side to side, the gaskets are bad and need replacement. They are very expensive, on average $10 per injector, so a 6 cylinder can cost $60.00 for good seals. The electrical plugs are generally pointing up. You might be able to tell which way by just laying the wiring harness out and seeing which way it looks like it should be connected by it's shape and where the connectors come to lie when they are dias-connected.

Should be tight/firmed otherwise its gonna leak fuel and create a vacuum leak-