05 Trailblazer I put new spark plugs in and then no throttle response,checked fuel pressure an is within specs but bleds off fast. Will not stay running and has not set any codes? Whats going on?

when did this PU run good last decade or found it in a barn for $200 dead (history matters)
1995, what engine OUR means POUR, yes, took awhile on that.
what we call instant start fuel (spray) runs short time..
so you lost fueling !
so check all fuses. for good for sure to FI and ECU.
check fuel pressure next . (rail pressure) to spec cranking the engine using hand held fuel pressure gauge, a tool.
3 second spray is par for 3 seconds run time , this test.
can repeat the test many time but 3 times is good to know the engine sounds good. no odd noises.
keep face away from TB so if it backfires, no burned up beard.

2.4L , real name is. (read nissan name, as all engine do)
is: as wiki or VIN decode shows

2.4 L KA24E I4 (1990–1997)

KA24E
SOHC 12valve head, hoohoo a nice chain drive cam.! no stinking belts. to snap and bend valves.

if compression over 150psi
check fuel pressure. if starting fluid test fuel sounds GOOD,.'
check fuel pressure, if too low it will fail to inject.
if low check FPR for bad, that is not old and stuck open as they do. FPR mounts to fuel rail and love to fail this old.
some wear out and jam full open returning all fuel back to the tank an no spec pressure is attained


if fuel pump checks dead, make sure fuel pump fuse and fuel pump relay works right
and sends 12vdc to the pump cranking,
that is it. base on engine seems good. (so far)
PS:
a new cap and rotor and wire sit be wise for distributor this old and spark plugs. a real spark tuneup.

no shop can fix it>??????? 5.9L gas.
cranks fast but no start has 50 causes (engine parts all+ EFI parts all)
a shop or tech does tests to do with tools .
if IAC is stuck close using 5% right foot throttle actions replace dead IAC lost air flow. so starts.
no need to buy IAC ever, seen right foot fail.
if it cranks fast why a new battery and alternator>?
300rpm is cranking speed, and is all you need
if battery stays above 10vdc (11 is par) the engine and EFI starts the engine.
compression tests pass on this old truck.


i WILL NOT GUESS FOR YOU. JUST TESTING

my list, (using real tools owned or borrowed)
IN ORDER (1,2,3 BAD ENGINE/SPARK/FUEL)

ALL FUSE TEST GOOD
SCAN PCM OBD2 PORT CRANKING NOW DTC'S POP UP.????????
26YEAR OLD ENGINES.
150PSI or more on all cylinders.??? NEAR EQUAL
DONE WOT WIDE OPEN THROTTLE.
NEXT.
SPARK TESTS GOOD AT ALL SPARK PLUGS.
NOT JUST 1, IF ALL DEAD CHECK COIL HV LUG NEXT FOR SPARK.
IF DEAD ICM DEAD?
I HAVE A TIMING LIGHT AND #1 FLASHES NEAR TDC MARK SO CAM OR DISTRIBUTOR TIMED RIGHT..
EVER TRY NEW SPARK PLUGS FIRST , CAP AND ROTOR OR ICM IF MAIN IGN COIL IS DEAD.
OK SPARK IS GOOD, AND SO IS ENGINE
NEXT IS FUEL,
WE NOW TRY TEST FUEL CALLED INSTANT SPRAY START IN A CAN. SOLD AT WALMART EVEN.
I SPRAY IT IN THE IAC HOLE OR AIR CLEANER PULLED AN SPRAY FOR 3 SECONDS THERE.
IN THAT HUGE AIR INDUCTION HOSE.
IT RUNS THE ENGINE FOR 3 SECONDS EACH TRY.
AND ENGINE SOUNDS GREAT.
MUST.
IF YOU GET THIS FAR OUT COMES FUEL PRESSURE GAUGE (HAND TOOLS)
CHECKING PRESSURE ONLY CRANKING A 2 MAN JOB. FOR SPEC. psi pressure

dribble test only finds dead pumps never bad FPR
ask scotty this, 5 million have.
keep in mind time limits then on videos
doing fuel tests is a 30min video alone,
leak down tests, injector balance test and FPR tested
cranking and idle and WOT. 3 tests.

https://youtu.be/064Ilsz8Fzg

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/

If your 96 Ford F250 starts up and then immediately shuts off, there could be several potential causes. Here are some things you can check:

1. Fuel delivery: Make sure the fuel pump is working and delivering fuel to the engine. You can check the fuel pressure with a fuel pressure gauge to see if it is within the proper range.
2. Ignition: The ignition system is responsible for starting the engine. Check the spark plugs, spark plug wires, and ignition coil to see if they are in good condition.
3. Engine management: The engine management system controls the fuel and air mixture going into the engine. Check the mass air flow sensor and the throttle position sensor to see if they are working properly.
4. Throttle control: Check the throttle cable to make sure it is moving freely and that the throttle body is clean.
5. Engine vacuum: Check the engine vacuum hoses to make sure they are connected and not leaking.
6. Security system: Some Ford trucks are equipped with a security system that can prevent the engine from starting if it doesn't recognize the key.

If you're unable to locate the problem or if the problem persists, it's best to take your vehicle to a qualified mechanic to diagnose and repair the issue.

Sounds like an air lock, have you bled the fuel line after fitting the new pump?

Get one of your local "tuner teens" to plug into your computer and reset the injector pulse width. Those kids seem to have all the latest gadgets to reprogram the computer.

Your fuel pressure release port is near the ignition coil packs on the fuel rail nearest cabin. Remove Schrader valve with core tool and affix a rubber hose and catch can. Turn key momentarily (Listen for pump) to "On" no starting. Turn key off and check can for fuel. If no pump hum was heard, check pump relay by swapping in another that's there in box ut, not equip. needed for eng. start like A/C. Test again. If you have fuel in the can, know you have spark,compression,and clean throttle path then, I would check/test fuel pressure.Chrysler spec. is 58psi +or- 5psi. If fuel pressure is there but below spec., my experience leads me to believe that the fuel filter above the tank is impacted and requires replacement, a line is kinked,or the jumper line within your new pump asssembly has a loose fit male to female connection and is bypassing fuel or sucking atmosphere at that union point.

For engine to run it has to have:
Fuel, air and spark.
So if it doesn't start, something's missing.
Is your fuel pressure OK? Is your spark present? Is ECM firing injectors?
Check all those basics and I'm sure you'll find what's wrong.

The fuel pressure is too low,replace the fuel pump

check the throttle position sensor.or any oil getting leaked from the throttle body.if its leaking then the oil needs to be cleaned from the throttle body. check out.keep updated.thanks.