TRE

How hard is it to change the spark plugs in a SC4 1992-1996 models? What tools do I need? Is it a progect to I can do by myself?

One more question. How do you clean the throttle body on the SC4 92-96? I hear guys talking about this, is it worth it and what benefits do you get?

Thanks,

Treon

TRE

:eek:Hello!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

lspower

do it youll notice better throttle response
i just did it today its much cleaner, im happy w/ the results

good luck

http://www.lextreme.com/tb.htm

HotBoy

I am doing it this weekend.
It depends how handy you are with cars.
I can pretty much tear down and rebuild one so it isn't that hard. If you are at a meduium level you can do it yourself.
For the throttle body clean you need to take the whole thing off because the carbon is in the part you can't reach through the butterfly valve.
I believe you need to take this iff to get at some plugs anyway so this is a god time to do this.
Do a search and there are som einstructions. If you can check the board regularly and can wait until Sunday I will post my how to for you or you can pm me with any questions.
PEACE

PERRYinLA

I followed those instructions posted at www.lextreme.com/tb.htm and was able to clean up the area just aft of the butterly valve pretty well (section C in the photo below), but HotBoy's right- there's only so much you can get to through the butterly valve. To get the rest, you should not only remove section A, but B as well. But remember that most driveablilty problems are caused with deposits building up on the butterfly valve area, which is easily accessed and cleaned by just removing A.

The lextreme.com instructions are for an LS. For my 92 SC400, I found 2 minor differences:

1) There is only 1 butterfly value, not 2 like on the LS
2) There are 3 fasteners securing the cover of the throttle body linkage (E), not 2 like on the LS

The instructions are excellent. I found that old sweat socks placed over a stiff garden hose made an excellent swab for cleaning- think giant QTip. The only extra thing I did was schmear a little vaseline around the rubber gasket between the air intake and the throttle body to make it easier to remove the next time you take it off.

HotBoy

hey man is that pic of a 92SC$ engine ?
I have a 92SC400 and I have 2 connectors on the D section it looks a little different. I am planning on taking the whole thing apart. Is there a gasket that goes between B and the intake ?
I would think so but it has never been mentioned.

PERRYinLA

Yes, that's a photo of my car's engine, and mine is a 92 SC4 (it only becomes an SC$ when the dealer wants to service it) , manufactured in early 92 and first sold in California in May 92.

And yes, there is a gasket 'tween B and C.

SeattleGS400

iTrader: (1)

Perry:

Did cleaning your throttle body help out with the idle? Also, did you get any other improvements--like the better throttle response that LSPower got? Just curious to see what cleaning the throttle body out would do.

PERRYinLA

I have yet to drive it, having only just cleaned it a few hours ago.

In my case, I doubt if I will notice any difference- the car is already running fine (knock on wood). I only did it 'cause it's never been done on my car and I was curious to see how dirty mine was. After checking out the instructions, I thought it would be a good preventative maintenance exercise.

It did have a thin layer of crud on the aft side of the butterfly valve, but it was not thick enough to interfere with either the movement of the valve or the valve's ability to make a good seal when shut. As for the rest of the deposits, it's nice to remove them (the 4 sweat socks I used turned a revolting shade of tobacco-stain brown) but I don't see how those deposits were harming anything- it's not like they are going anywhere or can interfere with the airflow.

In a worst-case scenario, it may do more harm than good. Imagine a very thick coating being loosened by the SynPower cleaner, and then chunks of that goop falling not into the rag but rather into the intake passages and gumming up the valves. If you find heavy deposits after removing part A, be sure to remove part B and proceed carefully.

SeattleGS400

iTrader: (1)

Thanks Perry--good info

Carpe Diem

The spark plugs are also pretty easy. They're located under those plastic covers on top of the heads. I think those are held on by 10mm acorn nuts. To do the plugs, you'll need a 3/8 drive rachet and a standard spark plug socket. Also, having one of those univeral joint swivel thingies and extensions in various length will allow you to get to them without taking much else off. Probably 1-1/2, 3 and 6" ones will do it. Don't forget to put some anti-seize on the threads of the new plugs for the next person who does the job.

George

PERRYinLA

I'm glad I saved my old sweat socks in my rag box- I knew they'd come in handy some day!
(But I think I'll throw these away now....)

HotBoy

See the difference in the TB and the connectores mine is also a 92Sc400 sold in cali, strange . I guess I need the TB gasket. Oh yeah and an SC4 transforms to an SC$ when you hold the shift key too long.

PERRYinLA

That is weird! Some other differences are that you have the "TRAC" logo on the throttle body linkage cover (E), the oil filler cap and the tubing against the firewall look different.

Golly, Hotz, if only we had a focused photo, maybe we'd spot other differences, too!

HotBoy

That is wierd man can anyone explain this ?
2 cars same year sold in the same state supposed to have the same engine.
When I bought this it had near 200k miles on it now it has 213k and still runs like new dealer maintained to the tee and documented before I bought it, like every minute detail, I'll check the 20 odd pages of maintenance I have to see if that TB isn't the original one.
PEACE

Oh yeah can I reuse that gasket for the TB, it is Sunday and if I can I will do the job today otherwise it will have to wait until next weekend.