graffda

I'm clueless While looking around the driver side of the engine generally below the EGR valve (which I had recently removed, cleaned, and reinstalled. For no good reason I partially disassembled the step motor on top of the EGR valve, which I have concluded nobody in their right mind fools with) I came upon this part. I fished it out off the top of the engine directly below the EGR valve. Does anybody have a clue as to what this is and where it goes?

RA40

iTrader: (6)

Uh oh...spare parts. I looked briefly at the diagrams of the EGR, starter and intake but ???

PureDrifter

iTrader: (10)

looks like a spring washer that belongs on the inside of some stepper motor

graffda

"looks like a spring washer that belongs on the inside of some stepper motor"

I suspected that since my helper removed the EGR valve and out of curiosity partially disassembled stepper motor, (when I wasn't there to witness), I had him show me extent of his removal again, and with the step motor and valve ( or whatever the part name is that goes up and down) removed I dropped what you are calling the "spring washer" into what looked like a seat for it, flipping it over both ways to judge its nesting appearance/fit and looking for evidence of nesting fit/marks. It maybe looked like a fit, however, I was not only unsure it belonged in there, but also could not decide which side was up and fearing I might do damage under operation, I left it out. I subsequently took the assembled EGR valve to trusted independent Lexus mechanic for a show, tell and test and he said he had never taken one apart to know. He bench tested the EGR valve and visually concluded the stepper motor turned the valve and it "worked" however, as I mentioned above he said he had never disassembled that particular one to know what was inside. Consequently, with a new EGR gasket, I reinstalled EGR valve.

Next, I removed and replaced the 2 upstream oxygen sensors with Denso brand (with electrical harness preinstalled) since I have currently failed emissions here in GA with high co numbers and concluded this was my next step. Then test drove 6 miles to and from DIY car wash and I was impressed with the engine feel and response. Subsequently, car sat for 3 hours, then a few moments after starting out at slow speed I was startled to feel hesitation that made me feel like it might die so I nursed it up to speed to complete very short ride home. After sitting for 10 minutes, figuring I needed to run/warm car up good for both, another emissions test, well as have computer adjust to new oxygen sensors, I made a few short around town shopping trips followed by 40+ minutes of vigorous interstate driving during which I felt none of the previous hesitation event but to my consternation, I noticed the "trac" light came on without the check engine light. I repeatedly shut down the engine and restarted to see trac light not come back on until I hit the 2200 rpm mark while in "drive" on interstate, while completing my pre emissions test heat up. Then upon consulting with emissions tester that, despite saying he would not automatically fail me for the trac light being on during the test, he strongly recommended I drive it for a few days before another test. So that is where I'm at now.

I should sum up by saying car seems to:
1. runs smooth and strong
2.warmed up engine idling in park with A/C off is 1000-1100 rpm, which I believe is high and ought to be closer to 500
3.trac light comes on, with no check engine light, @2200 rpm, even with traction control button set in off position
4. spring washer not installed in EGR step motor and therefore has no home

My plan is to do more research into both high idle and trac light coming on @ 2200rpm,

THANK YOU ALL all for reading and appreciate any thoughts.

Don Graff

peterls

Pretty sure that goes inside the "Valve assembly, idle speed control (for throttle body)" - idle speed solenoid. It is part number 22270-50010 on 1st gen.
It is important to put it back in there the right way, so that it pushes against the core of that solenoid. On my car, that part can opened and cleaned. On others, I think that may not be the case - it is sealed shut (mine has three little screws so I can open it).
here is the picture of that part, the thing you posted here is inside:

graffda

What a relief to hear! I am in the process of going thru all top side accessible EGR, idle related, vacuum and throttle body Preventative M and enjoying finding lots of Corrective M, going thru IAC valve has been pending.

Puzzles remaining include locating MAFS wire in hiding inside plastic shell and whether or not to clean if uncleaned in first 310,000, the last 120,000 may have certainly have been missed under my watch by previous mechanics, some of whose boners I'm turning up. Big thanks to you PeterLS and this forum!

I can't wait to get LS past emissions, now 90 days late, to max potential!

graffda

Thanks for your effort RA40! As a new thread starter Im making forum mistakes, recognizing your input shall not be beyond correction.

peterls

Grafda, if you are going through all the little things that make a big difference, I strongly suggest you do a proper radiator flush using Prestone Radiator Flush and Cleaner.
LS cooling system has some narrow passages and it does not take long to get those clogged up. You put in the Prestone with distilled water only, and drive like that for a few
days (say, 100 miles). Then flush that and pour in the Toyota coolant. I was amazed with the difference that simple flush made.

UNCNOR

iTrader: (1)

Please be more specific as to the "difference"Thanks

jaaa

I wondered the same thing as to how you could tell a difference after a flush.