How do you know when the fuel pump go's bad on a 2001 Mazda protege Lx?

Answer 1

If the fuel pump fails, fuel pressure will drop dramatically, causing noticable driveability issues. possible results could be lack of power, hard starting, stalling under load, rough idle, no-start conditions. you can probably expect the lean condition caused by low fuel pressure to cause eventual catalytic converter failure due to high exhaust temp if untreated, you may notice overly high engine temperatures, O2 sensor failure, and the MIL (malfunction indicator lamp) will come on as the PCM reports lean conditions, fuel pressure out of acceptable ranges, fuel pump failure or issues. due to the possibility of Mazda having not installed a fuel pressure monitor, the PCM may not know the cause of the lean condition and will attempt to modify pulse width to compensate. if it is unable to, a fault code will be logged. additionally, if left untreated long enough, a lean condition can cause the aforementioned cat failure, or may cause hot spots in the cylinders causing premature detonation. if you suspect a fuel pump failure, i would recommend one of two paths. if you have the equipment and information, check the actual fuel pressure at idle, part throttle and WOT against spec. if you do not have the ability to do this, go to the dealership and suggest you think it may be a fuel pump issue. if you wish to diagnose this, you should find the OBDII connector (data link connector) under the dash/steering wheel. most aftermarket code readers are relatively inexpensive and may tell you what the issue is. remember NOT to clear the codes or freeze-frame data, as this can not only cause the issue to worsen as the PCM relearns the problem, it may cause OTHER issues. also, it's a hassle for the garage you take it to.

Note: Fuel line pressure should be 270-310 kpa (39-45 psi)

Fuel hold pressure 150 kpa (22 psi)