hi everyone, so for the last few days my 1zz hasnt been running properly, its hard to describe but when im slowly accelerating in low revs the car seems to judder almost like its surging in small short bursts,also spitting and back firing quite alot,its also worst under load..this dosent happen if my foot is flat to the floor thou, ive cleaned my maf sensor and changed the plugs but that doesnt appear to help the situation, ive also had my autolec check it out but he says that all the ignition and fuel delivery seem to be working properly.atm im waiting for my pfc data logit box so i can record wats going on but im not sure it has anything to do with tuning as this is the first time its happened, am i looking at a mechanical problem?? any ideas at all would be muchly appreciated.