Alex, with the idle going up and down like that It could be a , vaccum leak , or the TPS sensor , Did you have the TB P/P ? If so it might have been ported a little extra around the blade area and you are getting a little extra air coming in if so you will need to fill the hole in the TB blade and get out some drill bits and start small and work your way up its a royal PIA but thats the love of modding ...Barrow a stock TB from a Miami SFFBA member and start there maybe. If you were closer I would let you try the one off my 99....

As far as using oil some LS1's just consum more then others <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" /> My old 99T/A would use a Quart every 1K but my 98 will go almost 2500 miles and no oil loss. My Formula uses about 1/2 quart every 2k but I change it by then since it gets the snot beat out of it <img border="0" alt="[driving]" title="" src="graemlins/gr_driving3.gif" /> You may want to do a leak down on it <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

<small>[ March 12, 2003, 11:28 PM: Message edited by: Street Racer ]</small>

 

I am having an idling problem. Several times, my idle has gone up as high as 1200 RPM instead of the 800 level. I will be doing nothing more than city driving and the RPMs will start normal and then go up to 1200 and back down to 1000 at the lowest. I have turned on and off the A/C to see if it had anything to do with it and it did very little. The car still idles too high. You can even feel it when you leave it in gear and are slowing down that it is like if you still are giving it some throttle and it does not slow down as quickly.

I have a 99 LS-1 with the following mods:
Free ram air, lid, descreened stock maf and ends, the bellows is not stock- it is a straight one instead of the stock accordion type, LS6 intake, EGR delete, Comp Cams 218/224, 525/537 with 114 LSA, port and polished stock heads (comparable to a stage 1), Mac mid-length headers, !CAT, Borla (it was open then I closed it off until I get the McCord installed). I have LS1 Edit and AutoTap.

The car initially was running on stock program with certain things deleted to stop the SES lights from the EGR delete and air pump and I deleted the rear O2’s. So they are not throwing codes. The 99 engine is in a 2000 car because the original engine was no good! The engine was running fine before the mods and was stock until installe in this car. So if it could be any installation issues, let me know. The car ran fine with a noticeable cam lope with the open exhaust. Then I closed the exhaust and it ran fine for at least two full weeks before I notice the high idle problem. In addition, I have had an oil consumption issue. Anywhere from ½ a quart to a full quart every 1000 or so miles.

I don’t think capping the Borla off could have caused the problem after the car was driven quite a bit with it that way and actually ran smoother and was MUCH quieter! I have checked the air intake temp readings, the throttle position, and several other things with AutoTap to see if I can see if something is out of whack, but the problem has not returned since I have checked it with AutoTap. I will be removing all the oil return lines and using a valve cover breather instead. This should lower my oil consumption, but I still think it is too high.

What ideas does anyone have for me to look at. Any advice or thoughts are appreciated. I will be taking the car in to dyno tune next week and I was hoping to have these two issues resolved before then so that I can have the car running its best. But, if I cannot then I will just have the dyno shop look into it while they are at it.

Thanks in advance!

 

is this a new thing? sounds to me like a cam that needs more air. the IAC sensor is going nutz. TB blade hole stock size?

 

The TB is stock. The car has been running close to 3 months with the current setup and did this on and off for about three days and has not done it again. I checked the throttle position with AutoTap and it went back to 0.4% everytime and idled fine. I have not been able to AutoTap it during a problem. The engine never consumed as much oil and I think it may be the PCV, which I will be removing and going with just a breather instead. The only thing that has changed recently and before the problem is that I capped the Borla off completely and was running it open before. But it took atleast two weeks before the problem came up. The last few days have had no problems.

Could it be a bad maf sensor? Also, if any you have AutoTaped your cars during normal idle and have any readings for throttle position and rpm and air intake temp and so forth, please let me know.

Thanks