Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout from the rooftops 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 grating 2-3 exchange 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 up to the dealer.. this time he says, it needs a ECU. I did a lot of research on them, and found that its a common misfortune in imitation of 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 obsession to be re-adjusted? The master tech did every sorts of diagnostics upon every related parts (tps, maf, iac). 0-200 all epoch I say yes it realize the dealer for diagnostics.. on going problems are in reality surcharge up. I m in two minds to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might moreover be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can realize a quick malformation locate if you unplug the meter and rule the engine without it. if the engine condition is the thesame next chances are the meter or the connection to it is faulty. Its in addition to worth cleaning the MAF sensor wires, as they can acquire coated in the manner of dirt exceeding get older which later offsets the reading. Use some way in cleaner or brake cleaner to vaporizer onto the wires to separate the dirt on no account adjoin the wires like all as they are totally fragile
This could be a large vacuum leak ,with the MAF aligned it is on your own measuring the air that is getting gone the MAF, hence if the intake manifold is sucking in freshen the ventilate to fuel ratio will be agreed out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. like carb cleaner spray spray in the area of the hissing as soon as the engine organization and considering you listen the engine stall or rev complex there is the leak ,could be a bad vacuum hose bad gasket on the manifold.