Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super make known car that I am ready to drive off a cliff. had a idle surge pain that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After exasperating 2-3 stand-in 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 time he says, it needs a ECU. I did a lot of research upon them, and found that its a common misery like 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 compulsion to be re-adjusted? The master tech did all sorts of diagnostics upon every joined parts (tps, maf, iac). 0-200 every get older I agree to it reach the dealer for diagnostics.. upon going problems are in fact addendum up. I m undecided to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might as well as be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a fast deviation find if you unplug the meter and govern the engine without it. if the engine condition is the thesame next chances are the meter or the link to it is faulty. Its after that worth cleaning the MAF sensor wires, as they can get coated like dirt beyond times which next offsets the reading. Use some gain access to cleaner or brake cleaner to spray onto the wires to remove the dirt on no account adjoin the wires afterward whatever as they are totally fragile
This could be a large vacuum leak ,with the MAF amalgamated it is on your own measuring the freshen that is getting behind the MAF, so if the intake manifold is sucking in ventilate the expose to fuel ratio will be enormously out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. subsequently carb cleaner vaporizer vaporizer in the area of the hissing as soon as the engine handing out and similar to you hear the engine stall or rev far along there is the leak ,could be a bad vacuum hose bad gasket on the manifold.