Originally Posted by spoonhbk11

Hi, Honda Tech... I recently replaced a wastegate actuator on 18g due to faultys
diaphragm and afterwards the engine now sputters, lower idle, sudden loss of power (sounds like timing is off), slight buckle, runs lean for some reason ... Can it be that since I was tuned on the previous actuator which may have ripped diaphragm at time of tuning, cause new actuator to throw tune out of wack? Re-tune? I have checked various things... Car reads full lean at idle on AEM wideband gauge, cruising reads lean, wot reads 10s...runs hot...Car doesn't run like previous day prior to new actuator. As if there isn't any gasoline being added to mixture ...

Car is tuned on Hondata S300... Compression test turned out fine...plugs look in lean condition...sensors, cam timing is on point , valve adjustment is ok, spark plug wires was told are ok, I have got no errors codes, there isn't any exhaust leak (visible),new fuel filter, pump fairly new(Walbro),I haven't check injectors but was told that isn't problem, rotor/cap new, try to mess with ignition timing without timing light via distributor but no difference at all... Grounds are good... I would like to mention that I did remove wastegate vacuum line to test actuator via air compressor but was immediately put back in same place. However, when I was diagnosing engine I happen to move 5 outlet vacuum tee where my vacuum hoses attach to, I noticed the engine rpms rose for a split second & engine sounded good... was only a one time thing though...I try to mess with vacuum tee/hoses again with no luck...if I press throttle it will sound great but when idles settles, sounds really rough... Fuel pressure reads 40-45 psi at idle...Mechanic claims it isn't anything mechanical... Engine has been well maintained minus a few times of over-boosting for a split second up to 13lbs when tuned for up to 10lbs. due to previous ripped diaphragm actuator ( I had adjusted actuator arm to see if it would lower boost psi unknowingly knowing about ripped diaphragm being cause) it had ... Car still ran fine afterwards...

Please any input will be greatly appreciated! Thanks