Where is the relay box located in a 91 bubble chevy caprice classic? My car keeps cutting off and it isnt the fuel pump or injectors

You should be able to hear te pump(in the tank) run for 2 seconds when you turn the key to "run".Ifnot,locate the plug at the sender unit for the fuel tank(not sure if you will need to lower the tank to do this).You should get 12v on the(possibly purple) wire when you turn the key to run.If you do,then the pump is most likely the trouble.(Try swapping the fuel pump relay with one of the others-like the A/C compressor relay,before you do all of this-highly unlikely a bad relay,but not impossible).

There is fuel pump relay located under hood on the passengerside fenderwell! The should be 2 Cube like boxes on a bracket, I believe the right side 1 is the fuel pump relay!

there is no fuse for fuel filter! but slot11 is for fuel injectors! and the relay for fuel pump is on the passenger side under hood bracket on fender well

You would not. All air in a fuel line will come out when the fuel pump is pressurized. I assume you have tried pumping the gas pedal? Also try depressing the pedal halfway down when you try to start it, if not press all the way down and try. You may have bad gas in the line or a blown fuse for the pump. It is very likely that the pump may be bad. But there should not be any issues with air in the line. You could possibly also have bad fuel injectors.

Check out your oil sending unit, fuel pump and relay, check for power (might be a fuse), the ignition control module (which if you remove it, can be tested for free at AUTO-ZONE), any related wiring, pick-up coil (inside the distributor), and possibly the ignition switch. If I can be any more help just as away.

well if the pump is running have the pressure at the fuel rail checked,then make sure voltage is good at the injectors

THEY ARE FOR EVERYWHERE. I THINK THIS MODEL HAS NOT A RELAY BOX

check for a naked wire running metal aroun tuns and anywhere that there has been and kind of work done latley pls take time to rate this solution

Also do not let tank run low because fuel in tank keeps in tank pump cool. This is why the pump is in the tank.

Try checking fuel pressure again with a guage on the fuel rail. If you still notice the pressure is low and you know the fuel pump is good, the fuel pressure regulator may be bad. Sometimes you can tell by unplugging the vacuum hose from it and if you see gas that means the diaphram is leaking. If everything checks out with the fuel system a bad EGR valve or EGR valve solenoid can cause cars to sort of stall under half throttle. Good luck and keep me posted. If you found this helpful please rate this solution.

Thanks - Tech101