What should fuel pressure be on idle?
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. When an engine is idling, it may be pulling 20 inHg of vacuum, which translates to roughly 10psi.
Will low fuel pressure cause high idle?
Possible Causes of High Idle Speed The engine may be overheating, and the cooling system might need repair. The fuel pressure regulator may be operating at too low of a pressure and might need to be replaced. If the computerized engine control system is faulty, high idling can be one symptom.
How much fuel pressure should a 5.3 have at idle?
48 psi fuel pressure at idle.
What fuel pressure does a 5.3 LS need?
Spec for the 5.3 is 55-62 psi according to the Haynes manual. Fuel Pressure For example a carbureted engine typically requires between 4 to 7 psi whereas a typical GM LS engine runs on about 58 psi.
What should fuel pump pressure be at idle?
Pump capacities can always be higher than specifications, but should never be lower. So if you get a pump that is flow rated at 0.4 gpm and you install it in a vehicle that requires 0.5 or 0.6 gpm, the pump may supply enough fuel at idle and low rpm, but may starve the engine at higher loads and speeds.
How can you tell if your car has low fuel pressure?
You might also hear some spluttering while trying to start your car. If your car’s engine stalls while running or at idle, it is a clear sign you are having some problems with your fuel pressure. This may be due to fluctuations and sudden drops of the fuel pressure.
What are the symptoms of a bad fuel pressure regulator?
The symptoms are very noticeable, too. You may notice a very rough idle, rough acceleration, slow acceleration, and vibrations from the engine. There are also many causes of engine misfires. It can be a problem in the spark plug or the ignition coil.
When do you assume there is enough pressure in the injectors?
If the engine runs, they assume the injectors are getting adequate fuel pressure. If the engine cranks but won’t start, and they depress the service valve on the fuel rail and some fuel squirts out, they assume the injectors have pressure. They do, but the question remains, “How much pressure?”