What should fuel pressure be on a 94 Chevy S-10 4.3L Vortec?

Check the fuel pressure. Should be 55 psi. Here are a few possibilities
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Sounds like it could be the EGR Valve.If you can drive it and get up to 45-55 mph and it runs smooth then its the EGR valve that is stuck in the open position.I would take the EGR Valve off and clean the carbon out of it using a non-chlronated brake cleaner.

If you have spark and fuel it should start. You must have min 57 PSI fuel pressure for this vehicle to start if it is the 4.3 Vortec engine. Also the cam sensor and the crank sensor control the spark. Does it have the check engine light on and if so what is the code or codes does it have? Need more info to help you out more.

how's the fuel pressure?

i do believe it will not start with out it if you can hook up a scan tool to it crank the engine and look at rpms while cranking should read about two hundred forty rpms thats what fires the injectors the cam sensor tells the computer what cylinder is ready to fire next also scanner will set the cam timming.

cant lose prime...it gets primed everythime you turn the key off and back on for more than 10 seconds.

have you had the coil pack controller checked?

any Check engine light when its running?

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/sean_54c3a3dc48a7773c

it looks like you need more fuel to start your engine check for a bad fuel pressure regulator, measure the pressure it should have 55 psi less wont start cold

THE FUEL PUMP IS BAD.

if your losing fuel pressure after the pump runs the drain back valve in the pump has failed.

and i doubt that you are seeing enough fuel pressure to run a vortec engine.

low fuel pressure equals a non running vortec

I'd be replacing oil sender. GM have used oil pressure switch as a safety shut-off to fuel pump, when oil pressure drops off, as it would in a collision, due to engine stall.

these vehicles are known to have problems with the fuel pressure regulator/and also fuel pump. you need to hook up a fuel press gauge to see how many lbs.ther are. being off 1-2 lbs.from spec will cause a no start that will drive you crazy.