DONNOD

Hi folks,

Car runs a bit rough every now and then (not always though,most noticed on cold mornings), feels like engine is not coming into boost and losing power. I also get hesitation on high boost with half throttle (24psi). I have replaced the plugs (NGK ILFR7H), fuel pump (Walbro 255), MAF sensor, getting new NGK ignition coils and leads also front O2 sensor.... I was wondering if this could be a boost or vacuum leak or air temperature sensor??? But it's weird as the problem doesn't occur always! Dyno test was done and the power was dropped by 20kw@wheels compared to 5yrs ago when it tuned. I like to hear some expert advice. Thanks

Bhsj13

maybe do a compression check. how about the turbo wg actuator?

DONNOD

Compression test was done and they all seems to be healthy. Engine had no sign or missing or detonation on Dyno test. I was told, drop in power is normal it could be related to many parts especially the aging spark plugs, so I replaced all plugs with Brisk, engine ran fine for a couple of days after I started to get misfire #4 error code so re-gapped the plugs but the problem returned. So, I replaced Brisk with OEM NGK plugs and that fixed the problem.

if the turbo wg actuator ceased or stuck, shouldn't it be a problem that occurs every time I drive?

JKX

Boost leak?