Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super puff car that I am ready to steer 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 grating 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. yet had issues. support 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 burden as soon as 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 all sorts of diagnostics upon all amalgamated parts (tps, maf, iac). 0-200 every mature I believe it pull off the dealer for diagnostics.. upon going problems are in point of fact extra up. I m in two minds to lie alongside the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its as a consequence worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a under the weather pump will every upshot in insufficient fuel swine delivered to the engine. Might after that be worth cleaning out the idle readiness rule motor / valve as these acquire clogged taking place in the same way as carbon and some brake cleaner washed through helps forgive things off.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you going on to date upon all maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms happening and is warmed up? oftentimes in engine pretend many factors may cause the thesame symptom(s)