1994 gmc sierra 5.7 liter running problem

my 1994 gmc sierra will start after it sits for a couple hours but then after its been ran for 10 or 15 minutes if i step on the gas pedal it will stall out and i have to hold the gas to the floor to get it to start back up. i came to the conclusion that it is flooding it self out but im not sure what would be causing it. i took all the spark plugs out and they were wet so i burnt the gas of them and put them back in but the truck wouldnt start back up, it just kept turning over and trying to start. the truck has spark and enough gas to turn over

Welcome to AF. I'd check for leaking injectors and scan it and look for a bad coolant temp sensor, it would read cold even after warmed up.

its throttly body injection and i didnt notice any leaks on the 2 injectors

I know it is TBI, so on to the second suggestion.

i checked the temp sensor with an ohm meter and the resistance was around 11,000 which is what it should be for the temp outside (23-25degrees)

If it's just cranking now, possibly check your coil. My 94 was just turning over but wasn't starting i changed taht and it runs strong now. Other then that im gonan try to think of what it could be but the coil was the first thing that came to mind.

well the coil has spark and the wires do also so im not sure what could be causing the problem

Ok, so when it runs a while it dies out like it is flooded as you stated, I said check the coolant temp sensor , obviously under the conditions it stalls, it should read the engine temp by then, if it still reads 25 degrees that is your problem.

no it wont start anymore but when its 25 degrees out the motor is 25 degrees and i checked after the truck had been sitting all day

Yeah it's most def the coolant sensor,called a friend of mine " he's a master mechanic " and with what i have read i explained it to him and he said that , it's the coolant sensor, and i guess on our year truck they go out alot, lucky me =) hasn't happened yet. Hopfully you solve the problem

so the sensor is bad even if it reads 25 degrees when the temp of the motor is 25 degrees

If it won't start cold,and it is in fact flooding, disconnect one injector, give it time to clear out and see if it starts, then you must go on to what is holding the injectors open. BTW your last post was inadvertently deleted. Yes the coolant temp sensor could read 25 cold then stay there when warm, unusual though, even if it is bad you should get an inital start if it stuck at 25.

so what do you think would be causing the injectors to stay open

my brother tells me its the fuel sender but there could be many other things that lead to it and i dont want to spend a bunch of money on a sender and that not be the problem, also could the fuel pressure regulator be cuasing the problem?

Have you tryed bringing it to a mechanic? Atleast if it is somthing you can fix yourself you will get a direct answer to exactly what maybe causing the problem.

yea i had a mechanic look at it and he told me it was getting enough fuel to start it but it was flooding it out. i asked my auto tech teacher that had been a mechanic for 20 or more years and he told me it might be a bad egr valve or maybe a tps

ok so i hooked an ohm meter up to my CTS. the temp outside is 36.6 degrees and the resistance for that should be around 8000-8500(8.0-8.5) ohms. my ohm meter was reading 10900 ohms (10.9) which would read somewhere around 26-28 degrees maybe. chart: 23 Degrees=12300 ohms. 32 degrees= 9420 ohms. that is the ohm change between 23-32 degrees. it kinda seems like the CTS is reading a couple degrees below what the temp out is the warmer it gets but im not quite sure about this, i couldnt get the truck to start due to a battery with only 8 volts.

When you brought it to a mechanic did they hookup a computer to the pickup? Because if there is somthing wrong with your EGR then it would bringup a error code, that is what happened to my truck right when we had the engine replaced with a used one. The egr needed to be replaced but i dont really know if i would have had this problem since the computer was hooked up to it right after the engine was droped in and started for the first time in my pickup, and the problem was cought then. But i do know that if they were to hookup the computer to it that you would be able to tell exactly what might be causing this problem and it maybe somthing that relates to the computer "if your lucky" but from what u are saying , i do think it could possibly be a EGR Valve but that is a long shot to a list of problems that could make this happen. And, as to what you said about your Cts that is weird that is' running alot lower then the outside temp.... Dont really know much about that situation other then i would think since its prob fairly knew it should be running correct to specs for the vehicle not lower.....

I have to bring my truck in this wednesday i will ask there and maybe they can give me an answer .

Good Luck

well the truck started acting up right after i put the new radiator and new temp sending unit in. i went about 5 or 6 miles at the most and it started stalling out and starting only when the pedal was to the floor

i put that new CTS in the truck and it runs great now but im kinda worried something else might go wrong with it. it idles down and tries do almost die out sometimes.

and when its idling if you sit in the truck it shakes roughly. almost like its not running on all cylinders