I seem to have developed a fault on my 1994 Prelude vtec. I put a adjustable fuel regulator on a couple of weeks ago ad wasnt happy with it so i put the original one back on. Now i seem to have a funny noise sometimes when idling. Its like an air pocket hits the fuel or something cous you can hear that kind of noise from the engine and feel it in the car. Sorry its not a very good description. But its only since i changed over the regulators. I have checked the normal stuff like vacum leaks etc but no luck. Has anyone got any ideas???

Rob