How does a fuel return line work in a gas tank?
Any fuel which is released from the valve is passed through the fuel return line back to the tank. There are two types of returnless systems – Mechanical and electrical. Mechanical returnless systems simply relocate the pressure regulating valve into the fuel tank, directly after the pump.
How does a returnless fuel system work in a car?
A returnless fuel system uses an in-tank pump and regulator. A single fuel line exits the tank and travels to the engine. Pressure is controlled by a computer, which monitors a series of engine sensors to determine how much fuel to deliver. To regulate the fuel pressure, the ECU simply adjusts the pump speed or fuel injector rate.
What happens when the pressure is too low on a fuel return line?
If the pressure is too low, the mechanical valve restricts the flow leaving the manifold, increasing pressure. If the pressure is too high, it allows more flow to escape, decreasing the pressure.
How does the fuel line work on a Camaro?
The fuel line on my Camaro has a bunch of bends as it gets to the tank at the rear. There were a couple of the rubber lines that looked okay but were actually cracked. That allows air in and acts like a broken straw when you are drinking soda. That cured a lot of the longer starts.
What happens when you shut down the fuel return line?
During these moments, the fuel pressure regulator, temporarily, shuts down the fuel return line. As a result, boosting up the fuel pressure. So, using this information, the computer decides the strategy, that will result in the best performance of the engine.
Do you need to retrofit a fuel return line?
It’s an easy question to answer on vehicles that already have a fuel return line…or at least the routing room for one. Retrofitting a returnless system can get expensive, requiring a new pump, regulator, and plumbing. But that’s not to say your vehicle’s returnless system isn’t pretty darn good.
Where is the return line on a fuel pump?
That’s why the fuel filter in these setups is typically installed clocked with the secondary outlet (return line) above the main outlet to the carb. The pump constantly sends fuel to the filter. When there’s excess fuel, it fills up the filter until the fuel level inside reaches the return port.
How does fuel return to the fuel tank?
As manifold vacuum changes with engine rpm, the diaphragm moves, opening/closing a secondary passage for the fuel to exit and return to the fuel tank. For visual learners, here’s a cutaway image of a regulator, courtesy of Turbosmart: