Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super puff car that I am ready to drive off a cliff. had a idle surge suffering that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After infuriating 2-3 exchange 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. help to the dealer.. this times he says, it needs a ECU. I did a lot of research upon them, and found that its a common problem in the same way as 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 need to be re-adjusted? The master tech did all sorts of diagnostics on all united parts (tps, maf, iac). 0-200 all time I endure it get the dealer for diagnostics.. on going problems are in fact tallying up. I m in two minds to be next to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car in the works this morning, it starts occurring and runs at 1750 and within a minute or for that reason climbs greater than 2500.. It is meting out smooth though, just way progressive than it should be. I plus checked the throttle screw plate/return screw, carefully turned it out and nothing changed. put it back to exactly where it was. No vacuum leak sounds and every links verified. I quality fine very nearly them as I've been in there a bunch of times..
I'm reviewing your ask now, and will proclaim back as soon as your answer ASAP. Rgds Greg. What deformity codes get you have. Does the engine manage subsequently the MAF disconnected. behind the noisy hissing sound this could be your problem. This could be a large vacuum leak ,with the MAF linked it is abandoned measuring the air that is getting taking into account the MAF, in view of that if the intake manifold is sucking in air the expose to fuel ratio will be unconditionally out and cause the engine to stal