I've adjusted timing twice to fit my new turbo. It slipped the second time so I retimed and its held pretty good (so far?). But I got on it pretty hard yesterdy and when I let out it started to kinda knock or thump at idle. No haze or smoke or anything at idle. When it idles egts stay around 350* instead of normal 275*. Loosened injector nuts on fuel lines, each cylinder went dead or cut out when nut loosened and sound never changed any. Around 1700 rpms or higher knock kinda smooths out.

Could it be timing slipped very little??? any help or suggestions is greatful. Thanx!