Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super push car that I am ready to drive off a cliff. had a idle surge misfortune that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After aggravating 2-3 rotate used IAC s, I took it to the master tech at lexus. He said it was the IAC valve. He tried my used ones.. and finally a rebuilt one. still had issues. back to the dealer.. this times he says, it needs a ECU. I did a lot of research upon them, and found that its a common difficulty afterward this car.. bought a used one.. more trouble. had the indigenous one rebuilt by a specialist.. and that s where I am at now.. Put it in tonight and the car idles at 2k rpm. Does the TPS dependence to be re-adjusted? The master tech did every sorts of diagnostics upon all joined parts (tps, maf, iac). 0-200 all mature I agree to it reach the dealer for diagnostics.. on going problems are really count up. I m unsure to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car taking place this morning, it starts happening and runs at 1750 and within a minute or therefore climbs exceeding 2500.. It is organization mild though, just showing off superior than it should be. I as a consequence checked the throttle screw plate/return screw, carefully turned it out and nothing changed. put it encourage to exactly where it was. No vacuum leak sounds and all contacts verified. I quality fine more or less them as I've been in there a bunch of times..
gone I start the car, the engine surges stirring amongst 1200 and 2000 rpm encourage and forth. I changed the IAC and the TPS in imitation of no regulate in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to acclimatize the idle readiness screw to humiliate the rpm and it would sustain for a while. Now, the engine is each time surging to the reduction where I cannot drive it for startle of damage to the steer train. Any experienced solution?