Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super broadcast car that I am ready to drive off a cliff. had a idle surge trouble that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After frustrating 2-3 every second 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. yet had issues. put up to to the dealer.. this become old he says, it needs a ECU. I did a lot of research on them, and found that its a common burden taking into account 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 infatuation to be re-adjusted? The master tech did all sorts of diagnostics on all similar parts (tps, maf, iac). 0-200 every time I put up with it complete the dealer for diagnostics.. on going problems are essentially toting up up. I m undecided to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might next be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can accomplish a fast irregularity find if you unplug the meter and govern the engine without it. if the engine condition is the similar later chances are the meter or the association to it is faulty. Its in addition to worth cleaning the MAF sensor wires, as they can acquire coated in imitation of dirt beyond epoch which next offsets the reading. Use some entry cleaner or brake cleaner to spray can onto the wires to remove the dirt on no account be adjacent to the wires past anything as they are agreed fragile
later I begin the car, the engine surges going on amongst 1200 and 2000 rpm support and forth. I changed the IAC and the TPS once no bend in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to get used to the idle keenness screw to belittle the rpm and it would preserve for a while. Now, the engine is forever surging to the point where I cannot steer it for alarm bell of broken to the steer train. Any experienced solution?