Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super push car that I am ready to drive 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 exasperating 2-3 swap 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. help to the dealer.. this mature he says, it needs a ECU. I did a lot of research on them, and found that its a common burden once 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 infatuation to be re-adjusted? The master tech did all sorts of diagnostics upon all related parts (tps, maf, iac). 0-200 all epoch I put up with it complete the dealer for diagnostics.. on going problems are essentially adding up up. I m undecided to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car occurring this morning, it starts up and runs at 1750 and within a minute or so climbs more than 2500.. It is running smooth though, just habit innovative than it should be. I as a consequence checked the throttle screw plate/return screw, with intent turned it out and nothing changed. put it incite to exactly where it was. No vacuum leak sounds and all friends verified. I vibes fine practically them as I've been in there a bunch of times..
This could be a large vacuum leak ,with the MAF linked it is lonely measuring the expose that is getting afterward the MAF, therefore if the intake manifold is sucking in expose the let breathe to fuel ratio will be entirely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. behind carb cleaner spray can spray can in the area of the hissing following the engine dealing out and similar to you hear the engine stall or rev progressive there is the leak ,could be a bad vacuum hose bad gasket on the manifold.