cylinder not working

I have a 94 eclipse with cylinders in the rear I am using smc 3/8's valves and cannot get it to lift under its own power. I am running two 3 gallon tanks and a 145psi switch. It also has a huge fiberglass speaker box with 4 12w3's (aprox. 500lbs) It did go up once on its own but will not anymore. I checked for leaks and found nothing major to cause problems. Any help would be greatly appreciated.

What size cylinders are they?

3" is what was in the kit

did u check the lines running to the cylinders.........oh and what kinda cylinders are they???

Try bumping up the pressure some. I have 3.5s in the back of my wagon and it will barely lift it with one sub and a full tank of gas.

Maybe a hose is pinched.

they are are from the devil (AIM). I thought about bumping up the pressure. I think I have a 170 laying around. Also th e way I have my tanks is one feeding the other not teed after the compressor and on tank hooked to the front valves and one tank plumbed to the rear.