Mystique problem/2000 mystique

The 2014 Chevrolet Malibu with the L4-2.5L engine does not have a 'typical' fuel pressure regulator. This vehicle has a fuel regulator valve (same function, just 'smarter' than a regulator). The pressure relief regulator valve replaces the typical fuel pressure regulator used on a mechanical returnless fuel system. Output drivers in the ECM provide the pump control circuit with a 12?V pulse-width modulated (PWM) signal, which regulates fuel pressure by closing and opening the control valve at specific times during pump strokes. On this vehicle, the regulator valve is built into and part of the high-pressure fuel pump. The high-pressure fuel pump is located on the rear, driver's side of the engine. For an image location view, click here: https://bit.ly/3mgrSAv. Before replacement, make sure to inspect the electrical connector and wire harness for any loose, broken or damaged wires. And the rubber lines for any cracks, holes or disconnections

A faulty fuel pressure regulator may result in engine misfires, reduction in power, poor acceleration, and a decrease in fuel efficiency. That said, the symptoms can also take place owing to other mechanical issues.

The Fuel Pressure Regulator is attached to the fuel pump and that whole assembly is located in the gas tank, beneath the rear seat. AFAIK there is only the one unit, not one for each bank. You can test to see if you have sufficient fuel pressure at the fuel filter.

copy and paste
https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-fuel-pressure-regulator-2328074170

is mounted on the fuel rail under the intake manifold

Hi Cesarjim,
The fuel rail pressure transducer measures the fuel pressure right at the injection site, ensuring that the fuel pressure value passed to the ECU is both accurate and precise.

I hope that answers your question.

Regards,
Jeep Brainy

How many fuel lines are going to the fuel rail? If there is only one line that you have a later model 2000 and the system is considered return less. This means that the fuel pressure is regulated at the fuel pump before the fuel gets to the fuel rail. If there are two lines going to the fuel rail than the fuel pressure regulator has to be in between one of those lines and the fuel rail

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

There is not really a fuel pressure sensor. There is a fuel pressure regulator. The fuel pump pumps up pressure and the pressure regulator allows the fuel to return to the fuel tank if the pressure reaches 37psi in the 4.6 liter. It is located on the intake manifold. It is round about 3 inches in diameter, and has a fuel line on both sides of it.

More than likely, yes. If the regulator is controlled by a vacuum feed, try removing the hose from it and run the engine. If you feel that it will run off-idle after you've done this, replace the regulator and be on your way.

COULD BE THE FUEL RAIL PRESSURE SENSOR OR YOU HAVE THE WRONG FUEL PUMP FOR THE VECHICLE.PCM COULD BE OUT OF CALIBRATION.TURN OFF RADIO FIRST THEN DISCONNECT NEGATIVE BATTERY CABLE FOR A MINUTE THEN HOOK BACK UP NEGATIVE BATTERY CABLE.THEN CRANK CAR UP LET IT GET OPERATING TEMP BEFORE THROTTLING IT.GIVE PCM TIME TO RECOGNIZE THE NEW FUEL PUMP.

This vehicle is most likely a returnless system,only one fuel line to the fuel rail. If it is returnless the fuel pressure regulator is part of the fuel pump module in the tank.

The fuel injectors may need to be cleaned. Also the issue could be the fuel pump or fuel pressure regulator. You can test this by renting a fuel pressure guage from the auto store and hooking it up to the fuel rail on your engine. The port you hook it to is called a schrader valve and looks similar to a tire stem valve. If the pressure is low the problem could be either the fuel pressure regulator or the fuel pump. Good luck and if you found this solution helpful please rate it.

Thanks - Tech101