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 hardship that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After frustrating 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. put up to to the dealer.. this epoch he says, it needs a ECU. I did a lot of research on them, and found that its a common problem taking into consideration 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 craving to be re-adjusted? The master tech did every sorts of diagnostics on all linked parts (tps, maf, iac). 0-200 every epoch I resign yourself to it pull off the dealer for diagnostics.. on going problems are essentially totaling up. I m in two minds to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might then be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can realize a fast malfunction 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 furthermore worth cleaning the MAF sensor wires, as they can acquire coated following dirt exceeding mature which later offsets the reading. Use some contact cleaner or brake cleaner to spray onto the wires to surgically remove the dirt on no account lie alongside the wires with all as they are definitely fragile
when I begin the car, the engine surges going on in the company of 1200 and 2000 rpm encourage and forth. I misrepresented the IAC and the TPS in the manner of no modify in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to get used to the idle quickness screw to humiliate the rpm and it would support for a while. Now, the engine is all the time surging to the dwindling where I cannot steer it for radio alarm of damage to the steer train. Any experienced solution?