has anyone come across this problem; when i let my car (2001 mazda 323 sp20) idle in neutral the rpm starts the surge and what i mean by that is when let the clutch out in neutral the cars rpm goes from 1000-1500 constantly going from one to another, once i engage the clutch it goes back to normal idle (750 rpm), another thing i when i disengage the clutch and don't press the brakes the idle just stays at 1500 rpm, recently this happened when there appeared to be a whole in the intake piping, i thought this was my problem so i replaced my intake piping and this didn't fix the problem so it still surges when the clutch is disengaged and when the clutch is engaged it goes back to normal idle (750 rpm), any help is appreciated.
Thanks in advance
Thanks in advance