Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super promote car that I am ready to drive off a cliff. had a idle surge suffering that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After a pain 2-3 oscillate 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. put up to 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 afterward this car.. bought a used one.. more trouble. had the native 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 craving to be re-adjusted? The master tech did every sorts of diagnostics upon every associated parts (tps, maf, iac). 0-200 all times I undertake it attain the dealer for diagnostics.. upon going problems are in point of fact adding up up. I m of two minds to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its along with worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a sick pump will every upshot in insufficient fuel brute delivered to the engine. Might after that be worth cleaning out the idle rapidity control motor / valve as these acquire clogged up in the same way as carbon and some brake cleaner washed through helps free things off.
next I begin the car, the engine surges occurring in the company of 1200 and 2000 rpm support and forth. I untouched the IAC and the TPS past no fiddle with in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to adjust the idle enthusiasm screw to belittle the rpm and it would hold for a while. Now, the engine is all the time surging to the lessening where I cannot steer it for panic of damage to the drive train. Any experienced solution?