2kd engine 2005 toyota hiace, did 2 scan/diagnostic which states that the (fuel system heavy leak detected), the issue I have when I'm driving at a regular speed the vehicle is fine, but when I come to stop or in traffic and pressing the gas pedal the vehicle either shuts off or not taking the rev, which I have to turn off the vehicle and restart it.

wow NO YEAR TOLD.
no car told at all,just vague 2kd , hint, (a true challenge that)
it is some kind of toyota, but they have vast vast models.
some models sold are 40 million sold by them.

real name and is a DIESEL.
2KD-FTV???????????? 2001 sold first in a hi-ACe truck never sold in USA< this truck.
2.5 L ,2005 CRS, common rail injections at 29,000 PSI. 2000BAR
seen first in UK market, so says WIKI, my guiding light to the no car told pit.

this engine is used in the Toyota Hilux, Toyota Fortuner, Toyota Innova and Toyota Hiace. In some Central and South American countries, Toyota also offered this engine on the 2003-2006 4Runner in limited quantities.
to get specks on car or trucks we need year and model
books are indexed and sold by year and model and country
that is how the world works , sorry.

my guess

1. bad fuel
2. injectors partly clogged
3. fuel rail pressure out of spec,
4. we scan it as some engines have rail sensor there. and moe.
5. filters clogged. any.

not bad glow plugs, as it does start.

Appearing in November"2001, the 2KD-FTV is the 2nd generation of the KD series of engine with a smaller 2.5 L (2,494 cc) displacement and went on sale in the UK market in the 2002 Toyota HiAce
so is HIACE and a secret>? name of car and year both a secret>
Diesel engine,
engine stalls may be lost of diesel fuel pressure to the injectors.
check pressure yet?

no HIACE here USA.
so no manuals to quote spec to you.
get the service manual for your truck and do the tests there.
for stalls.

http://travelwebs02.travelpirates.com/toyota_hilux_2y_engine_service_manual.pdf

After reading about the two engines, they use the same repair manual. I have not seen a swap but it looks like they are compatible.

Save the diagnostic checks until there is noting else to physically check, look at or adjust. Best practice is hands on - first!

Try checking the turbo boost pressure.
Check for restricted exhaust, especially if fitted with a particulate filter.
Check the operation of the egr valve.
Check all vacuum connections and pipes...

Black smoke means too much fuel .
Have you changed your air filter or is it clean. A dirty air filter will flood your engine.
Is your choke working properly?
Could be your carburetor float is sticking.
Not sure but there are computer sensors in some makes that could cause flooding if they are not working properly.
I am sure there are other things that could be the cause but you can start here.

fault code is missing a letter and first number
so its P0093 large fuel leak

the fault list has list of what to check
http://www.obd-codes.com/p0093

Fuel injector failure, Fuel line common rail leak, Fuel pressure sensor malfunction
Fuel pump or lift pump failure, Fuel heater constantly on Fuel temperature sensor failure ,

Leaks at any point in the high pressure circuit Electrical connector corrosion or seating problems
Fuel pressure regulator malfunction Fuel filter plugged dropping the fuel line volume Injector pump leak
Fuel control actuator failure
Cascade overflow valve malfunction Short in the electrical harness at the injectors or to the ECM Fuel pressure limiting valve ECM failure
Copyright OBD-Codes.com

The pump is probably ok from the tank but the injector pump may have been damaged if the filter failed and allowed particulate to enter the pump also the injectors themselves maybe clogged best way to check the pump is with an oscilloscope (lab scope) check the amperage waveform with the lab scope and calculate the rpm , also check the fuel pressure from the pump with an appropriate fuel gauge

ck for fuel leaks and ck the fuel filter , and the fuel pressure at the mainifold could be a bad pump same symptons filters are know for this issue,

check for fuel leak at the pump. pull and fit new tips to the injectors. Have the injection timing checked by an accredited diesel shop ( same one that is replacing the injector tips)