Will not Idle, Only starts if pumping gas pedal

TSTUEMKY

MEMBER
2001 MAZDA PROTEGE
2.0L
4 CYL
2WD
MANUAL
180,000 MILES

Hi there,

My protege lost engine power while driving down the highway at 70 mph. I have replaced the fuel pump which was going out anyway, and it did not solve the issue.

I am able to start the vehicle, but only if I pump the gas pedal which leads me to believe it is something with either the throttle body, or throttle body position sensor.

The vehicle will not idle after starting, and I have to keep the gas pedal engaged (above 2,000 rpm roughly) to keep the engine running, and it almost sounds like its running out of time, or running rich.

Is it worth my time to remove the necessary parts to clean the throttle body/ butterfly valve, or should I just test the sensor, or am I on the completely wrong path?

1 Reply

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello,

This might be a problem with a vacuum leak. Check all air intake tubes/ducts, throttle body, intake manifold, vacuum lines, evap lines for any air leak. This would be allowing in metered, or air the PCM(computer) doesn't know about into the combustion process. A good way to do this is with a propane torch. Turn the torch on it's lowest setting without lighting it. With a helper having your vehicle running, pass the torch around all areas talked about earlier. When the leak is found your engine should rev up as the propane gets introduced into the combustion process. Let us know what you find out.

Thanks,
Alex
2CarPros