JdmEG6559

idk for what reason my b16 started to idle very rough. it would idle from 800 to 1500 every time u go into neutral or when u step on the clutch to neutral it would start to idle again untill u put in in gear and step on gas then it stop. it only happen when it is in neutral. when its in cold start it doesnt idle back and forth but once it warm up and drive for a little it would idle even tho my temp. gauge is not at normal reading temp. yet. recently i check my cel code and its throwing code 23 and code 43. for code 23 i know that my knock sensor is bad, im not to worry cause im going to tune my car and eliminate the knock. for code 43 im not sure how to fix it. i did some research and code 43 is fuel system supply. as for the forums i found, it said it could be the fuel pump, fuel filter, fuel injectors, vacuum hose leak, leak on my fuel line or tank or a bad o2 sensor. so which of these is true and what should i fix or check first before making any changes. i recently change my fuel pump to a walboro 255lp and i know it working because when u turn on the ignition you can hear the pump pumping. i also replace my fuel filter not long ago so i know it is good. and as for the 02 sensor i will disable or eliminate it once i tune my car. ANY HELP to this problem.

civicguy395

i would start with the o2 sensor check the wiring

jbpnoman

They're all true. When you upgraded fuel pumps, did you have your car tuned for the new fuel flow? You should have. If you want a simple and quick possible fix, get an OEM pump and put it in your car.

If you want to go through the correct diagnosing process, do a complete check for vacuum leaks, then get a fuel pressure gauge and test your pressure at the filter. You should have 38-42 for the B series motor, after turning the key to ON(II). After reaching pressure, turn the key to OFF. It should hold pressure for a minimum of 2 hours, with a max fluctuation of 1 PSI. This process will diagnose pump, filter, and injectors all at the same time.

JdmEG6559

thank you for ur help. i already found out the problem it was a vacuum leak that is why it idle