How do I stop my compressor from prematurly turning on ?

You probably have a faulty pressure regulator. Try turning back the regulator valve to lower the cut-off pressure and see if that stops the compressor. If it doesn't, it's probably the regulator. Hope this helps.

Has the tool been lubricated properly to Hitachi's recommendation? Is the airline pressure running about 90-100 psi? If not try giving it more pressure. Sometimes the compressor may have too smaller receiver (Tank) for what you are trying to use it for, leaving the tool unable to return the piston/driver to top dead centre.

If your using refills that have wire holding the nails together.
Check to see if bits of wire, debris is collecting in around the striking hammer. I switched to paper and never looked back. Must have gone through 5k worth of nails and rarely jams. Other things to check,
1. Check the striking hammer, make sure it is not bent or damaged.
2. Check air pressure, Low pressure can cause jamming, misfires.
3. If the tool needs pneumatic oil, 2-3 drops before you start good rule of thumb.
4. Check spring return. Sufficient pressure must be maintained or the nails will not feed properly. Misfires, incorrect feed, jamming etc.
I had a Hitachi brad nailer and it was horrible. Fire 1 brad nail would jam or misfire. Did everything I could think of nothing worked. Put it up, got a Rigid brad nailer and never looked at the Hitachi again. :)
Sometimes you just get a lemon! (PS I understand you have a framing nail gun. Brad nail gun above is used for an example)
Hope this helps

There is an unloader valve and a check valve on the discharge side of the pump. The check valve is not holding and the unloader is not dumping the pressure so the compressor cannot start. Since it is new, you may want to take it back. If not you are going to be replacing parts.

Two things come to mind. The A/C system is overcharged cause the compressor to work hard and this will drag down the engine. The other is the compressor is getting ready to die. Again this will drag down the engine. If you can reach the compressor, with the engine off turn the front of the compressor ,not the pulley. It should turn freely, with no drag. and as you keep turn you will feel a pulse this is pressure building in it, this is normal. The freon pressure has to be checked with pressure gauges.

adjust your pressure switch on your compressor .remove the cap and turn the screw clockwise to increase and counterclockwise decrease.turn the screw counterclockwise a bit and release some air till the compressor start pumping.then just before to reach 120 psi turn counterclockwise to stop the compressor at 120.then release some air again till it cuts in again and look at what pressure it will stop.keep going that way till you get your 120 psi.cut in should be around 90 psi(30 psi differential)depending what kind of pump you have (if the pump can handle 150 psi )you can adjust it to cut in at 120 and cut off at 150 and install a pressure regulator adjusted to 115 to 120 and get a nice steady pressure going to your nail gun.(the best way to do it!!!)

Hello. To adjust the depth of the nail you have to increase or decrease the air pressure from the compressor. Look at the compressor and you will see a knob or dial that you can turn to increase or decrease the air pressure. Do this adjustment in small increments testing the nailer by driving nails into a scrap of the same material you will be driving the nails into on the actual job. Increasing the pressure will drive the nail deeper and decreasing the pressure will drive the nail less deep. Joe

lower pressure leaving tank into gun by turning pressure regulating knob if your compressor has one if it doesnt you may need to get one from lowes or hd.30 bucks roughly.

Your air pressure is dropping everytime you fire. It sound like your compressor is not cutting back in untill it to low. Not giving your tool enough continuess pressure. Your compressor cut in pressure should be around 90-100psi no less. and your max. pressure no more then 120psi. (Make sure your regulator is set at 110psi)
good luck...!

Set up the pressure on the air compressor. First plug the air compressor in, then check the pressure. It should be between 90 and 110 pounds per square inch (PSI) for home use. If it is not in this range, turn the knob to the left to decrease the pressure and to the right to increase the pressure. Use the appropriate nail gun for the job. For example, to nail shoe molding to base boards, a standard finishing nail gun would be perfect. It holds any size nail between 5/8 inch and 2 inches. This nail gun could be used for many projects with great results. Check the gauge the nail gun takes before purchasing the nails for the gun. If you get the wrong gauge they will not fit in the gun. You can check this by looking at the information printed on the side of the nail gun next to the model number. You can also open the nail chamber for this information. Attach the nail gun to the air compressor. You can do this before or after you load the nails into the gun. Use the air compressor hose to attach to the bottom of the nail gun. It screws on much like the end of a hose. If you do not have the right size air hose, you can find one at your local hardware store.