# How much fuel pressure does a 454 TBI need?

## How much fuel pressure does a 454 TBI need?

The fuel pressure regulator is set for approximately 12 psi (30 psi on ’94 & ’95 BBC trucks). With a service range of 9 to 13 psi being considered good. This equates to a 17% to 20% change in injector flow rate over the service range. Then the stock injectors are just large enough for the engine they were on top of.

## What should my base fuel pressure be?

With a return system, the base pressure is set with the engine off, but the pump running. For a GM, this pressure is usually set to 58psi (factory fuel pressure in the rail). When an engine is idling, it may be pulling 20 inHg of vacuum, which translates to roughly 10psi.

## What psi should a high pressure fuel pump be?

The high-pressure pump compresses the fuel up to 350 bar (5076 psi), depending on the load and speed of the engine. The fuel is stored in the fuel rail and sprayed into the combustion chamber through electrically operated high-pressure fuel injectors.

## What is the fuel pressure normal range?

between 35 and 65 pounds per square inch
It is between 35 and 65 pounds per square inch (psi) on most vehicles.

## How much PSI does a TBI need?

TBI only runs at about 15 psi. TPI needs more like 50-60psi.

## What happens if fuel pressure is too high?

Too high of pressure may result in, over fueling of the engine. As a result, this can lead to a rough running engine; poor fuel mileage, and black smoke coming from the exhaust. If your regulator is going bad, your car could display several different symptoms.

## How do I know if my high pressure fuel pump is bad?

Symptoms of a high-pressure fuel pump failure are:

1. Delayed start of the engine.
2. Hesitation or sputtering in acceleration between 2000 RPM to 4000 RPM.
3. High engine temperatures.
4. Vehicle stalling due to exertion or temperature.
5. Fuel pressure gauge reading low measurements.
6. Poor gas mileage.

## How can I get more power from my 5.7 TBI?

How to Get More Horsepower for the 1994 GMC 5.7 Liter TBI

1. Fill up your vehicle with high octane fuel rated above 90 octane.
2. Add fuel injector or carburetor cleaner to your vehicle’s gas tank every 3,000 miles.
3. Install a cold air intake on your vehicle’s air intake manifold.