Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super make public car that I am ready to steer off a cliff. had a idle surge problem that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After trying 2-3 substitute 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. nevertheless had issues. back to the dealer.. this mature he says, it needs a ECU. I did a lot of research upon them, and found that its a common misery bearing in mind this car.. bought a used one.. more trouble. had the original 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 infatuation to be re-adjusted? The master tech did every sorts of diagnostics on every associated parts (tps, maf, iac). 0-200 every time I say yes it reach the dealer for diagnostics.. upon going problems are truly adjunct up. I m in two minds to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might furthermore be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a fast oddity locate if you unplug the meter and govern the engine without it. if the engine condition is the similar after that chances are the meter or the association to it is faulty. Its along with worth cleaning the MAF sensor wires, as they can get coated in the same way as dirt greater than become old which later offsets the reading. Use some entre cleaner or brake cleaner to vaporizer onto the wires to remove the dirt on no account adjoin the wires following anything as they are unquestionably fragile
in the manner of I start the car, the engine surges going on amongst 1200 and 2000 rpm back and forth. I changed the IAC and the TPS in the same way as no regulate in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to become accustomed the idle keenness screw to degrade the rpm and it would support for a while. Now, the engine is continuously surging to the lessening where I cannot drive it for terror of broken to the steer train. Any experienced solution?