ok, I thought I would post some notes on my tune up today...

My 97 SSEi was running rough, idling was worse and slower to start when cold. It also did not have as much power as it used to, and had lost about 3Mpg on the highway.

I changed out my AC Delco Rapidfire plug with the same type (#14). I am really happy with these plugs, the old ones had done 41K miles, and still looked great. I would recommend these. As usual, got my arm bruised from those rear plugs, man those are tough. I pulled off the fuse relay cover this time, and it gave me another 1/2 inch to squeeze through.

I pulled off the Throttle Body and removed the MAF screen. Cleaned the 2 electrode sensors with Electronics cleaner and cleaned the rest with Throttle Body cleaner. The air intake side was pretty clean, so I thought it would be ok on the other side. Wow, the other side was caked on black muck. Took a lot of spray and scrubbing to get it clean, and I cleaned around the butterfly so it would open and close easily. Dont get throttle body cleaner on the electronic sensors.

I did a Supercharger oil change too. I did this about 50K ago when the car was at 90K miles. Well, last time, the 90K service showed the SC oil was black, thick and nasty smelling. Guys, if you havent changed the SC oil before, do it soon.... So its been 50K since the last change, and the oil today was still clear, slightly tan color, and didnt smell anywhere near as bad. Its pretty easy to change, sucking the old stuff out is the hardest, but the SC oil bottles from GM are made so you can just squirt it into the hole easily. Mine takes about 7oz to fill it to the bottom of the thread (thats almost 2x 4oz bottles)

Anyway, I am impressed with the differences now. Idling is really smooth, cant even feel the engine now. Acceleration is smooth and the SC boost is really good. Even my wife noticed the difference. Now I'll be interested to see the MPG figures, I am going to Michigan next week, so I will test it then.

So if anyone has any rough idling or dwindling performance, clean the Throttle Body properly. Dont use the gunk in your gas tank, pull the thing off, buy the cleaner and scrub it good. You will be amazed.

Cheers,

So when you removed the TB.. did you re-use the gasket? I haven't done mine yet, as when I did it on my old car 89 Crappylier.. the TB gasket ripped.. so reluctant to do it again on this..

Yes, I left the gasket on. Actually, I pulled the TB without thinking of the gasket, and the gasket wasnt in one piece. However, I thought I would throw it back together and get a gasket if I needed to. Well, the performance and smoothness is so much greater now that I'm gonna leave it as it is.

If you have a chance to get a gasket before you do the job, I'd get one.

Cheers,

is the the throttle body where the intake hose meets the engine? i would like to celan mine im just not sure how.

Yes.. the big accordian tube that goes from your airbox meets the engine.. it technically meets the TB.. if you look just behind it.. you'll see it'* held by bolts and lil gasket ends stickin out from it.. but remember.. there'* a MAF sensor thats on the inside top of of the TB that you'll need to take out before cleaning it

along, any difference in the idle speed after reinstallation of the TB? I recently gave mine the same treatment and the idle quality is greatly imporved but now the car idles at 1500 RPMs. I posted this topic the other day and tried the suggestions given but there was no change.

1500 rpms? All the time, or just at startup for a little bit? Double over all the connections that are remotely in the area of the TB. I don't think the IAC would be messed up but who knows?

Sounds like an IAC problem to me also.

when I first started it after the clean, the idle was high and rough. But after a few minutes, it settled down and is rock solid where it should be. Its smooth and quiet now.

I think if the idle is high, that would also indicate your gasket is bad or there is an air leak around the TB to manifold join. Extra air will increase your idle. I would change your gasket. Dont overtighten the nuts that hold the TB on though......

Also, I didnt take out the MAF sensor, but just cleaned it with electronics cleaner. I was careful not to get any TB cleaner on that sensor though.

Took my car for a long drive today, and have tons more power and its much more smooth under max boost. Maybe the SC oil change helped that, but Im more inclined to think its the TB clean considering how dirty it was.

Cheers,

It will idle high after cleaning it because its sucking in all the excess tb cleaner that is flammable. If there is a bad it will allow for a vaccum leak which would cause idle spike also.