New member needs help

[setaclay]

Hi everyone, I have a 95 SC 400 with 34k on it. Recently I had the engine degreased. When the engine is fully warmed up and I have been driving for 15 minutes,in gear at a complete stop the rpm drops down to a little over 400 rpm, and causes a little rough idle,that I can feel in the steering wheel. I brought it to Lexus, and they ran a diagnostic, the service rep said, it might be the Thottle body needs,cleaning, if that does not work, we might have to replace the motor,and if that does not work we might have to replace the computers. I dont mind paying for something if it is needed, but to play the replace game not knowing what it might be at my expense , well you get what I mean.

Does anyone have any tips, or has had this problem,that might be able to
help me. thank you.

 

[stevechumo]

Hi everyone, I have a 95 SC 400 with 34k on it. Recently I had the engine degreased. When the engine is fully warmed up and I have been driving for 15 minutes,in gear at a complete stop the rpm drops down to a little over 400 rpm, and causes a little rough idle,that I can feel in the steering wheel. I brought it to Lexus, and they ran a diagnostic, the service rep said, it might be the Thottle body needs,cleaning, if that does not work, we might have to replace the motor,and if that does not work we might have to replace the computers. I dont mind paying for something if it is needed, but to play the replace game not knowing what it might be at my expense , well you get what I mean.

Does anyone have any tips, or has had this problem,that might be able to
help me. thank you.

Your dealer's first advice might be true. Their second advice sucks and is a total rip-off. Don't ever do it. Their third advice could be true. However, it could be repaired. I got a similar situation like yours with the same car. If I turn off the A/C at the intersection, the car stalls. I took my '95 SC 400 to a Toyota mechanic and he told me the computer has a problem causing the low RPM and the engine stall. And then he replaced the stronger springs (I don't know what springs) that are related to the throttle body & A/C function. My car was now just fine. Last but not least, that Toyota mechanic told me that many dealers just rip-off their customers on repair. He's been working for several Toyota dealers for over 20+ years. In my opinion, you should take your car to a trusted Toyota specialist and see what he says.

 

[Peewee]

Not trying to be harsh here, but let this be a lesson to NEVER EVER EVER clean the engine/bay with more than a rag and a can of degreaser.
I am presuming here than a high pressure water sprayer/degreaser gun has been used? If not, I apoligise for jumping to conclusions.

That said, remove the spark plug covers, pull all the leads out, and look down the spark plug holes. There is a chance than water/degreaser has gone down the holes, and is causing bad spark. Use some rags to make sure there is no moisture there at all.

It is also possible that the throttle body is dirty.
Pull the intake piping off (the plastic bits), spray some throttle body cleaner on the throttle plate, and clean it with a rag. Open the throttle plate and clean the back of it, and the inside of the throttle body.
Don't worry about getting any of this stuff inside the motor. The car may blow smoke for a few mins after you use it, but don't worry, you haven't done any damage.

Last thing would be to clean the ISCV. Its the black round thing at the front of the intake chamber. 3 screws and it comes off. Make sure the plunger is nice and clean, as is the seat it sits on.

 

[Lextreme II]

I think the water moisture is affecting your ignition system. You might want to make sure your tps, isc, maf and rotor caps are moisture free.