Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super announce 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. encourage to the dealer.. this get older he says, it needs a ECU. I did a lot of research upon them, and found that its a common trouble taking into account 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 dependence to be re-adjusted? The master tech did all sorts of diagnostics on every related parts (tps, maf, iac). 0-200 every get older I take it complete the dealer for diagnostics.. upon going problems are truly totaling up. I m of two minds to be next to the tps if he had it dialed. Any insight? Thanks in advance. Jason
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me tell you a tiny more nearly the problem history. It currently has a master tech approved idle freshen run valve and tps installed. without distressing anything, the last (used) ecu and my original, would manage in the car without this symptom.
I'm reviewing your question now, and will state assist considering your answer ASAP. Rgds Greg. What fault codes do you have. Does the engine manage subsequently the MAF disconnected. in imitation of the noisy hissing strong this could be your problem. This could be a large vacuum leak ,with the MAF related it is deserted measuring the expose that is getting behind the MAF, hence if the intake manifold is sucking in let breathe the freshen to fuel ratio will be very out and cause the engine to stal