I have a 93 rocky petrol efi ,i can't stop the full pump from pumping ,truck has been under water came up over cpu 'cpu was beeping,is this y its doing that

Try a scrap yard or an Isuzu dealership.
Fleabay may even list one.

If you are sure the fusel pump is losing pressure or stops working check the EFI relay in the fuse box under the hood, check to make sure the EFI fuse is not loose or cracked, locate the circuit opening relay it controls the fuel pump and try a new relay, if nothing else replace the fuel pump, another possibility is the air flow meter, there are contacts inside that turn the fuel pump on and off as the meter door opens and closes.

Possible throttle position sensor or low fuel pressure under a load.

Here's a Autozone repair guide on your water pump. Repair Guides Engine Mechanical Water Pump AutoZone com

why not just use voltmeter, to check all fuses for hot both sides? key on. (need a video?)_
why not post symptoms then ask a question.?
must we send for ever looking for that which doesnt exist.?
and did you know there is more than one engine?
and both are wired different with different EFI systems?/
4A or 7A? engine, its a toyota corolla btw.


eg:
pump pressure is zero. (gages)
i check relay, the FP relay is closed.
i check the relay input and no 12vd.
sure bad fues, is there is one.
but on many cars , lots of other things go dead too. with this fuse.

ill now guess 4a engine with coin toss. vin code 6, engine,
i open glove box. and see the book the opr guide (yes buy one)
and turn to fuse page.
or login to alldata.com and stop guessing.
i look under prizm and corolla, 93 for best clues. (big hint, wink)


this EFI has 2 relays, one is the main relay,
other is fuel pump
the main sends power to the pump relay.
so there are 2 fuses,
one is marked
EFI-Fhtr fuse
and
IG coil. fuse

the main relay drops out of the transmission A/T is not in park or netral.
if manual stick car, the clutch switch does the same

alldata.com

look up your car, your trans, your engine.
and see the schematics.

Remove the drive belt.
Disconnect the two hoses (one pressure, one return) from the pump... catching the contents of the pump's reservoir with a pan under the vehicle. Crowfoot six-point fitting wrenches are strongly suggested for removing the hoses.
Unbolt the pump from its bracket.
Remove the pump.
Replace with a new or rebuilt or salvage pump, reversing these steps.
After refilling the reservoir to the full mark, start the engine and turn the steering wheel fully against both right and left stops several times to bleed air out of the system. Top off the reservoir to the full mark again.

Are you sure it's running when cranking? It should have come on when key turned on.
This is for camrys up to year '91. It may apply in your '95, also. Check the 7.5 amp ignition fuse and the 15 amp EFI fuse and the EFI main relay, all located in the fuse box next to your battery. There is also the circuit opening relay tied in to fuel pump operation. It is usually found under center of dash. It is usually not the problem, but it is part of the checks for fuel pump operation.
If your car has a " check connector" or "service connector" (also called a fuel pump check connector) under hood on driver's side near the firewall (a little 1 inch cube with a cap on it), then bridge terminals +B and Fp with a jumper wire. Turn key to on (don't start car). The pump should come on. Listen for fuel return noise from the fuel pressure regulator, and verify pressure in hose from the fuel filter. If nothing, check those fuses above. Here is how power runs to pump: Battery to 40 amp main fusible link-to 15 amp EFI fuse-to EFI main relay-to circuit opening relay-to fuel pump-to ground. Ignition switch and the computer (ECU) work the relays to pass power to pump. Hope this helps some, Randy. Good luck.

Check your oil, I borrowed my mother in laws truck like this it had no oil pressure well it didn't have any oil. If you have oil you have a weak oil pump or your oil passages might be clogged up. You could also try running a thicker oil like a 10-40 instead of a 10w-30, or maybe add some oil honey something like that. Hope it's just low on oil that would be the easiest fix.

check the crankshaft sensor as this is where the signal to fire comes from

I would check the fuel pump relay under the dash in the passenger side and check the efi relay first. After that i would follow the wires to the fuel pump and the engine harness for any shorts.