Moet_lowlyfe

have a 98 ls400 with a 1uzfe and just last year i encountered this same problem. On a cold start it ran well until the motor was at operating temperature then would drive like s#*t as if it was mifiring. A few times the vsc light would come on check engine light stayed on. So i took it to my local shop found an air leak on the intake box, changed plugs, did a compression test all cylinders passed. Put it all back together and still did the same thing. I took it to another one of my mechanics who had a better diagnostic computer codes came back and said faulty vvts (variable valve timing solenoid) replaced those as well as removed the valve cover and cleaned the screens. I must say for 400xxx miles there was not any serious sludge. Put it all back together and still same problem. Later i changed timming belt ,tensioner, idler, guides even put new vvt cams in. Problem still continued, my buddy had a ecu that we tested and problem continued to occur. So as of rii now car has been sitting for more than a year

I have a 98 ls400 with a 1uzfe and just last year i encountered this same problem. On a cold start it ran well until the motor was at operating temperature then would drive like s#*t as if it was mifiring. A few times the vsc light would come on check engine light stayed on. So i took it to my local shop found an air leak on the intake box, changed plugs, did a compression test all cylinders passed. Put it all back together and still did the same thing. I took it to another one of my mechanics who had a better diagnostic computer codes came back and said faulty vvts (variable valve timing solenoid) replaced those as well as removed the valve cover and cleaned the screens. I must say for 400xxx miles there was not any serious sludge. Put it all back together and still same problem. Later i changed timming belt ,tensioner, idler, guides even put new vvt cams in. Problem still continued, my buddy had a ecu that we tested and problem continued to occur. So as of rii now car has been sitting for close to 2 years not sure if anyone knows the problem