Fuel pump is bad. At idle pressure should read 50 PSI. Replace with original manufacture fuel pump after market pumps will burn out fast and are unreliable from my experience. Also could have a bad fuel regulator but that only works while driving down the road full throttle. You can unhook the fuel rail pressure regulator and that will give it full fuel and the pressure reading should read 60 PSI while it is running. If you turn the engine off and turn the key to run position it should read 50 PSI and hold for 60 seconds, if it drops below 30 PSI after 30 seconds Pump is defective. Many pumps are going bad here of late as people have been running them less than ¼ tank and this kills the pump. The fuel cools and lubricates the pump so the lower the fuel level the worse it is on the pump below ¼ tank. Not to hard of a job to do if you want instructions let me know.
hi bruce, i have a mazda 3 1.6 and i have just change my fuel pump assembly recently, what i want to ask is that i have a hard starting and i couldnt reach the desired rpm even if im at 4th gear, my rpm would only reach 2000rpm and i can only run at about 45kmph, could there be a problem in my fuel pressure how can i check it, tnx in advance..
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U will need to replace the fuel pump, pressure should be 60PSI
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