Silverado barely idles. stalls when adding throttle

This is complex to diagnose. Here are possibilities:

Here are some possible causes and solutions:

Fuel pump relay: A faulty fuel pump relay can cause the fuel pump to stop working intermittently, which can cause the engine to stall. You can check the fuel pump relay by swapping it with another relay of the same type in the fuse box. If the problem goes away, then the relay was the issue. If not, then you can move on to the next possible cause.

Clogged fuel filter: A clogged fuel filter can restrict the flow of fuel to the engine, which can cause the engine to stall. You can check the fuel filter by removing it and blowing air through it. If there is no resistance, then the filter is not clogged. If there is resistance, then you should replace the filter.

Vacuum leak: A vacuum leak can cause the engine to run lean, which can cause the engine to stall. You can check for vacuum leaks by spraying carburetor cleaner around the intake manifold, throttle body, and vacuum lines while the engine is running. If the engine RPMs increase, then there is a vacuum leak.

Faulty idle air control valve: A faulty idle air control valve can cause the engine to stall at idle. You can check the idle air control valve by removing it and cleaning it with carburetor cleaner. If the problem persists, then you should replace the valve.

Faulty throttle position sensor: A faulty throttle position sensor can cause the engine to stall when the throttle is opened. You can check the throttle position sensor by using a multimeter to measure the resistance across the sensor terminals. If the resistance is not within the specified range, then you should replace the sensor.

Faulty mass airflow sensor: A faulty mass airflow sensor can cause the engine to stall when the throttle is opened. You mentioned that you already changed the MAF, but it's possible that the new MAF is also faulty. You can check the MAF by using a multimeter to measure the voltage across the sensor terminals while the engine is running. If the voltage is not within the specified range, then you should replace the sensor.

Faulty ignition coil: A faulty ignition coil can cause the engine to stall when it gets hot. You can check the ignition coil by using a multimeter to measure the resistance across the coil terminals. If the resistance is not within the specified range, then you should replace the coil.

K1500 PICKUP. ? 5.7 TBI. GAS
i will assume eng. compression good and spark good and timed by the book.
it's staving for fuel.!
fuel pressure not at spec,
fuel pressure regulator bad.
injector clogged (injectors screens inside packed)
bad fuel (was bad now bad fuel is in all that path)
MAP sensor bad or clogged up. EGR stuck open
meter mAp pin out,1.5vdc out,keyon to 4.5V WOT (wide open throttle)

we test fuel pressure 3 ways
key pressure
idle
and WOT
the manual covers that, buy the service manual?
so the pressure specs for TBI are at hand./?
there is no fuel rail like MPI so has very odd connections to do pressure tests TBI. (below)
you do know most injectors have 10micron screens inside,and only ultra sonic reverse cleaning cures them right? (or new injectors) I send mine out for pro cleaning, (Usonic)

the hard part of 1995 TBI is getting the TBI specs.
the manuals were 500 pages paper and nobody digitized all page or skipped most the Injection pages.
it is a problem but the used books are sold at EBAY
from GM (real)

rumor has it
"In stock form a tbi operates 11 to 13 psi running a bit higher makes them run better to a point of about 14.5"
the TBI if you look close has a FPR, seen here
it must be good.(diaphragm)
some TBI have 2 injectors, start+idle (and fast run)
as seen here

https://www.rockauto.com/en/catalog/chevrolet,1995,c1500+pickup,5.7l+v8,1031443,fuel+&+air,fuel+injection+pressure+regulator,6124


next up how to read the pressure (tap ports)
I think this is a returnless system (early)
so they make up filter tap point. fuel. or TEE fitting.


https://www.reddit.com/r/MechanicAdvice/comments/10nz5rd/best_way_to_check_fuel_pressure_gm_tbi/

Check for vacuum at map sensor.check fuel pressure.

Fuel filter,air filter,IAC sensor,Bring up low idle at throttle body is small set screw.

ck fuel pressure ,map maf sensor.timing .

Have you checked the cam sensor? Also does that vehicle have a "throttle position sensor"? Some cars use both MAP and MAF sensors, not sure about your particular vehicle but if it is one of those, cleaning the MAF wouldn't hurt. Good luck.

I put a new fuel pump, fuel filter, and a fuel pump relay and the fuel pump is still not coming on. I am not getting any fuel. Can you please tell me what it might be.

idle control valve maybe

either fuel filter stoped up , air filter, the egr valve stuck open ,or a vaccum leak

your on the right route but also check egr valve