Here is picture of My 92 LEXUS SC 300
Diamond White Pearl
Factory 5 speed Manual
Very Clean interior, exterior and engine
No Mechanical and Cosmetical Issue, Clean title, No Accident

As you may aware that this Lexus manual is rare and transmissions swap directly to Supra Turbo GeTrac6(6 Spd)
there are many other part that swap from Supra including brake.

I love driving this car, it comes with all factory powered options and not a drip of oil left in the garage.

I like to change oil / filter my self. It has been using MOBIL 1 and K&N/Mobil 1 Oil Filter.

SC300 have the sleek look that i like and driver is sitting in the middle of the car (notice the long nose and the rear. And the soft leather, I admire LEXUS interior.

DETAILING ENGINE VS ROUGH IDLE

I always like to keep my car clean, especially in the engine bay. And many of the engine detailer spray would require to flush with water. The problems comes up when water is the enemy of electrical component.

Monday morning when i was going to work, i notice the engine had a rough idle and acceleration was bad. It take longer to achieve 60 Mph from 0 Mph (its like towing a big boat). I remembered washing my car on weekend might have cause the problem.

After work, I decided to repair it my self. I tried the loooong extension cord with Hair Dryer thing.. Hmm..Doesnt work (all my neighbor was watching me with strange grin ... lol)

WHAT YOU NEED:
- Rachet
- Extension rachet
- 12 mm socket, and I think is 1 long 17 mm socket (for the spark plug)
- Pliers
- WD40
- 2 Bottle of Thottle cleaner (I use Valvoline)
- Lots of Rags
- Hexagon screw driver or Hexagon "L" Key (For the engine cover)
- Scewdriver (+ & -)
- Patience (you can do this faster, if you already used to it)
- Sanding paper (to clean the spark plug and distributor)

CLEANING DISTRIBUTOR
- I remove the distributor cap (3 screws) clean the spark contact area with sanding paper and cleaner, and there was no moisture.
- install back distributor, start the engine. I notice that engine still have rough idle.

DETECTING WATER IN CYLINDER??
- this step is necessary, try to unplug the spark wire from distributor one at a time, while engine is running, check if there is spark coming from distributor. You should do this ONE WIRE AT A TIME. When you unplug a spark wire from distributor, the engine should stumble. Put the wire back on. Then move to the next wire
if you unplug the wire and it has no effect on the engine, that means that the cylinder in that area doesn't get spark from distributor.
- On mine, I detect number 4 cylinder was the problem,
- Unfortunately the cylinder 5,4,3 are under the Throttle body.

REMOVING INTAKE TUBE
- With screw driver you need to remove the intake tube that goes to TB, loosen the clamps with philips (+) srew driver
- cleaning the intake tube with cleaner and rags.

REMOVING ENGINE COVER
- This is the hexagon cover on the Engine (6 hexagon bolts)

REMOVING OXYGEN SENSOR BRACKET
- There is a Bracket (4 nuts 12mm) that hold the Trottle body. remove the nut and slide off, put aside. unattach the oxygen sensor bracket.

Picture was taken when i install things back, notice TB was sooo Clean, Clean, Clean.

REMOVING TROTTLE BODY
- Remove the trottle body (2 nuts 12mm, 2 long bolt 12mm) you can get the 2 long bolt very easy on the top of TB.
the other 2 nuts is at the bottom, if you have rachet and extension, it will make life whole easier.
- Unplug clips from sensors (there are two sensors attach to TB)
- Unplug all vaccum lines (i believe there are 4 at the top)
- unplug the coolant entry lines (2 lines) one at the top and another has a small clamp with (-) screw driver.
- Unlatch the acceleration wires, you need to hold the round metal part while sliding the small metal drums (on the end of the cable) off.
- I would rather leave the acceleration wire adjustment alone.
- Slide it off and viola...

REMOVE TB METAL GASKET
- Remove Throttle body gasket, slide it off and put away in clean place. Do not bend it.

CLEANING TROTTLE BODY
- I use Valvoline throttle cleaner, spray 1 bottle to clean the inside, work that butterfly and spray more

CLEANING THE INTAKE MANIFOLD
- you can clean the intake manifold, since we are already here.
- I put rags or towel to absorb drip to the spark plug area (see Picture)
- Nice and shine.

CLEANING EVERY SPARK PLUG and wire contact
- just like what is said, pull the wires up and clean the wires contact to spark plugs (I prefer to do this
one by one, so I would now how to put it back properly)

This is the picture of the Spark plug Valley in the middle of the engine, prone to get water puddle causing rough idle, picture taken from above
- Removing Spark plugs, i'm using BOSCH PLATINUM 4, It was pretty dirty.
- you can plugs the hole with rags (where the spark plug was) and clean the valley with cleaner,
(get a cleaner that would evaporate and ok with plastic).

Its getting dark, so i continue this the next morning

PUT EVERYTHING BACK (TROTTLE BODY, Vaccum lines, coolant lines, clutch wire, the Oxygen sensor bracket, Intake tubes)
RESET ECU (unplug the EDI (green fuse 30 Ampere) for 10 sec, located in the engine bay)
DOUBLE CHECK EVERY CONNECTION TO THE TROTTLE BODY

Completed engine, I detailed everything as I go. (Might as well do it when im there)

Now this is the one million dollars question, cross your fingers, and start the engine
Engine should run rough with high idle, as its trying to burn the Valvoline cleaner that i srayed for cleaning the intake manifold. Then it should come down to 750 RPM and purring as a cat.

Now my lexus engine is smooth, rough idle is no more and the power is back.
I'm Proud of my self.....

LEXUS SC 300, White Diamond Pearl
Manual 5 Speed
ALPINA SOFTLINE SPONSORED LIGHT WHEELS
225/30/17 Michelin Sport Pilot
265/40/17 Pirrelli P-Zero
HID Lights, 165 watt Off-road High beam
Nakamichi Premium Sound Systems
Eibach Lowered Suspension
Upgrade Custom Rear Exhaust
K&N Intake Filter, Mobil 1 fluid.
No Dings, Smooth Paints.

LINKS and USEFULL STUFF:

- www.lexustuner.com
- Lexus Forums:
www.clublexus.com
www.lexuspros.com/cgi-bin/YaBB/YaBB.cgi
- How to remove cabin filter: http://web.ace.net.au/soarer/air_conditioner_filter.html
- How to remove and change stereo:
http://carstereohelp.com/stereoremovalLexusSC300Str.htm
- Lexus parts:
http://www.lexus-parts.com/
http://www.taprecycling.com/