On a 92 Chevrolet s10 c/k 4.3litre TBI fuel injection pickup,,what can be causing loss of power wenpressing on gas? Otherwise,it run great.

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/

Question heavily edited for clarity and typos.
Question moved from Smart for Two, to Chevy S10.

This could be a job that goes like a dream, or it could be a 2 week snagging job to get it to run right, or even run at all. They are both 4.3 and fuel injected so that's good.

You will need the ECM from the vehicle the engine came from, and it may need reprogramming.

https://www.google.com/search?q=tbi+4.3+engine+to+gen+3+conversion

..

Front of the intake as I showed you in the other question you posted.

SKM, fuel pressure regulator is on top of throttle body. This could be the problem, could also be vacuum leak, faulty EGR, etc. You may want a good Tech, to diagnose and estimate repair. Check the attached links,instruction and guides, Good luck
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TBI 220 Fuel pressure regulator change 1
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Look under the truck and find the gas line coming out of the fuel tank and follow the line until you come to the fuel filter. Once you find the fuel filter unscrew it and place a liquid fuel pressure gage in the line and roll the truck over and read the fuel pressure. Hope this helps.

Have you checked fuel pressure with a gauge ?
Is the check engine light on ?
Will it rev up in park or neutral ?
Normal exhaust flow ?

try idle air controller

check your fuel pressure if it has the CPI injection pressure should be 58-65 psi with key on engine off.If your motor has the TBI throttle bodt injection your fuel pressure should be 9-13 psi with engine running.

I have a 90 chevy k1500 350 tbi with same problem! I have traced problem to... after turning on key fuel pump kicks on when u crank it over injectors shoot gas and truck starts! After few seconds injectors stop spraying and truck dies! This can happen many times over and over! Eventually sometimes truck stays running and all is great! I changed ignition module, oil pressure sending unit (which i was told controls gas after vehicle is running) fuel filter, computer, fuel pump relay, I am at a loss now! Hope this helps and hope someone can help me!

This injector set-up needs a specific fuel pressure supplied to the fuel rail to even start, much less run properly. The fuel pump is immersed in fuel inside the gas tank to keep it cool and not burn up. Running the fuel level low causes more heat in the pump and interuptions in proper fuel pressure. AC/Delco pumps have proven to be a reliable fix, the aftermarket pumps only last for a month or two sometimes. Check fuel pressure under the hood and power and ground to fuel pump at electrical harness at top of gas tank. This truck needs a fuel pump.