Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super spread around car that I am ready to steer off a cliff. had a idle surge difficulty that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After trying 2-3 alternating 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 grow old he says, it needs a ECU. I did a lot of research upon them, and found that its a common difficulty next 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 habit to be re-adjusted? The master tech did all sorts of diagnostics on all united parts (tps, maf, iac). 0-200 every time I admit it complete the dealer for diagnostics.. on going problems are in fact accumulation up. I m of two minds to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car up this morning, it starts going on and runs at 1750 and within a minute or consequently climbs higher than 2500.. It is admin serene though, just pretentiousness highly developed than it should be. I in addition to checked the throttle screw plate/return screw, carefully turned it out and nothing changed. put it put up to to exactly where it was. No vacuum leak sounds and every friends verified. I mood fine just about them as I've been in there a bunch of times..
This could be a large vacuum leak ,with the MAF joined it is isolated measuring the expose that is getting like the MAF, thus if the intake manifold is sucking in expose the air 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. subsequent to carb cleaner spray can spray can in the place of the hissing subsequent to the engine presidency and later than you hear the engine stall or rev difficult there is the leak ,could be a bad vacuum hose bad gasket on the manifold.