Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super spread around car that I am ready to drive off a cliff. had a idle surge trouble that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After frustrating 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. nevertheless had issues. urge on to the dealer.. this era he says, it needs a ECU. I did a lot of research upon them, and found that its a common burden next this car.. bought a used one.. more trouble. had the original 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 every amalgamated parts (tps, maf, iac). 0-200 every mature I acknowledge it realize the dealer for diagnostics.. upon going problems are in reality accumulation up. I m in two minds to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
I did re-check them tho. The master tech did extensive tests on the expose flow meter and said it was good. following I unplug it and govern the motor, the car runs rude and at 850ish. I can lonely guess that my supplementary rebuilt ecu has an issue, or the tps needs to be re-adjusted, or anyhow my maf has died in the midst of every this. I don't think the tps has that much manage in the rotate of rpm though? I think it unaided adjusts it re 1k..
This could be a large vacuum leak ,with the MAF linked it is unaided measuring the let breathe that is getting later than the MAF, consequently if the intake manifold is sucking in freshen the expose to fuel ratio will be categorically out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. taking into account carb cleaner spray spray in the place of the hissing following the engine doling out and considering you hear the engine stall or rev far along there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.