2001 silverado 4.3 fuel pressure only 30 psi will that stop it from running pour gas into throttle body start until uses up the gas?

30 PSI of fuel pressure is significantly low for a 2001 Silverado 4.3L. The specified fuel pressure is typically in the range of 45-60 PSI, depending on engine load and conditions. This low pressure will absolutely hinder the engine's ability to run properly, and likely explain why it runs only when you add fuel directly to the throttle body.

The fact that it runs briefly when you add fuel directly into the throttle body confirms a fuel delivery problem *before* the throttle body. The problem is *not* likely within the engine itself (injectors, etc.) because those parts work when fuel is introduced directly.

Here are the most likely culprits for low fuel pressure on a 2001 Silverado 4.3L:

* Fuel Pump: This is the most common cause of low fuel pressure. The pump may be weak, failing, or clogged.

* Fuel Pump Relay: The relay might be failing to properly energize the fuel pump. This is a relatively easy and inexpensive part to replace.

* Fuel Filter: A clogged fuel filter will restrict fuel flow, causing low pressure.

* Fuel Pressure Regulator: This regulator might be failing and allowing too much fuel to return to the tank, reducing pressure at the injectors.

* Leaking fuel lines or fittings: A leak between the pump and the engine will obviously lower the pressure.

Before you do anything else: Check the fuel pump relay first, it's the cheapest and easiest thing to rule out. Then visually inspect fuel lines for leaks or damage.

You should not continue running the engine by pouring gas into the throttle body. This is extremely dangerous. It's a temporary fix at best and could lead to engine damage, fire, or serious injury. Get the fuel system repaired properly.