Check the hose clips for tightness and examine the trunking for any cracks or splits and plus all the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best way to find a leak is to have the engine presidency and hot and then spray lighter gas /propane or brake cleaner on each joint in turn. If the engine rev s up you ve found your leak.
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me tell you a little more just about the burden history. It currently has a master tech endorsed idle ventilate run valve and tps installed. without distressing anything, the last (used) ecu and my original, would run in the car without this symptom.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you going on to date on all maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms stirring and is warmed up? oftentimes in engine measure many factors may cause the thesame symptom(s)