When does fuel pressure drop after turning off the engine?
When does fuel pressure drop after turning off the engine?
Turn the engine off, but key on and pressure gradually drops all the way to 18 PSI over 20 minutes. Turn the key off then key on but no engine start, I can hear the 2 second fuel prime and the PSI shoots up to 55 PSI and engine still has to turn over for 3 or 4 seconds without gas pedal, 1 or 2 seconds with gas pedal.
What does the fuel pressure regulator do when the engine is shut off?
Slow or No Start Part of the fuel pressure regulator’s job is to maintain fuel pressure at the fuel injectors at all times, including when the engine is shut off. Under acceleration, the vehicle should accelerate smoothly no matter how hard or light the gas pedal is depressed.
What to do if your fuel pump looses pressure?
To check the fuel pump, presurize the fuel system and only block off only the return line. If it holds pressure then you know the the fuel pump is ok and the problem may be with the fpr. If you loose pressure, the pump check valve is bad and you need a fuel pump. To check the fpr, pressurize the system and then block off only the feed line.
When do I lose fuel pressure on my Silverado?
I have a 2005 Chevy Silverado 1500 and I lose pressure gradually when I shut off the engine. When I go back to start it within an hour I cant get it to fire unless its turned over several times and I hit the gas. Ive replaced the fuel pressure regulator and ICV. No codes whats so ever.
What does it mean when your fuel pump is losing pressure?
Losing Fuel Pressure. If the system keeps pressure you know that injectors are ok and the problem may be down stream (fuel pump or fpr). On the flip side, if it didn’t hold pressure then it could be an injector or an fpr leaking into the vacuum line. To check the fuel pump, presurize the fuel system and only block off only the return line.
Slow or No Start Part of the fuel pressure regulator’s job is to maintain fuel pressure at the fuel injectors at all times, including when the engine is shut off. Under acceleration, the vehicle should accelerate smoothly no matter how hard or light the gas pedal is depressed.
What should fuel pressure be in a truck?
Fuel pressure test when cold, turn key on and spikes to almost 60psi, then quickly drops to about 10psi, but truck still starts ok. Holds pressure around 52psi. Turn key off and pressure drops rapidly. When motor hot, turn key on and climbs slowly mid 50s, then falls back down. Long crank and need to pump pedal to catch.
Why did my fuel pressure drop to zero?
The pressure dropped about 10 psi over the first half hour, then dropped all the way to zero within the next half hour. It has a brand new fuel filter also. I can find no visible leaks nor do I smell fuel. This leads me to beleive that either the FPR is defective or maybe I have a leaking injector.
What are the symptoms of low fuel pressure?
Low Fuel Pressure Symptoms & Causes 1 Unresponsive Throttle. All cars require proper fuel delivery to their cylinders in order… 2 Difficulty Starting the Car. Low fuel pressure will also make it hard for you to ignite your car’s… 3 Stalling Engine. If your car’s engine stalls while running, it is a clear sign you are having some…
What are the symptoms of a bad fuel pressure regulator?
Another symptom of an issue with the vehicle’s fuel pressure regulator is fuel leaks. If the fuel pressure regulator’s diaphragm, or any of the seals fail, fuel leaks can occur.
How long does it take to check fuel pressure?
Checking fuel pressure is very vital in diagnosing an engine performance issue. Depending on the application, it will take any where from a few moments to a few minutes to hook up a fuel pressure gauge.
Low Fuel Pressure Symptoms & Causes 1 Unresponsive Throttle. All cars require proper fuel delivery to their cylinders in order… 2 Difficulty Starting the Car. Low fuel pressure will also make it hard for you to ignite your car’s… 3 Stalling Engine. If your car’s engine stalls while running, it is a clear sign you are having some…
What should fuel pressure be when engine is off?
First, I measured with fuel pressure regulator vacuum hose connected to intake manifold. It was 36 psi, which is 2 psi higher than normal (30-34psi). Then, I measured with fuel pressure regulator vacuum hose disconnected, and it was 46psi, normal (41-46psi).
What happens if the fuel pressure regulator is not working?
If the fuel pressure regulator is not maintaining exact fuel pressure while the engine is running, it can cause the engine to run rich or lean, and in the event it goes too far in either direction, the engine will stall out due to an inability to properly burn the air/fuel mixture.
How is the fuel pressure set in a GM return system?
Fuel Pressure Explained. 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). The vacuum/boost referenced regulator will help to change the pressure in the rail based on the pressure in the manifold.
