quote:Originally posted by DanA_F99_1977: Steve, can you tell us about the problem with idle and how you solved it?
Thanks, Dan
Sure, Dan. The idle problem isn't so much with the cam as it is with the '99 and newer "Desired Idle Speed" at set by some moron at GM. The "DIS" is set at 650 rpm out of gear (Park or Neutral) and only 550 rpm while in gear (Drive, OD, or Reverse). This is where the problem lies. With the DIS set that low while in gear that idle speed won't adequately sustain any aftermarket cam but the very mildest. I might add that on the '98s, the DIS was set at 750 rpm in and out of gear, a much more sensible number. Anyway, because of the slightly rougher idle inherent in my relatively mild cam in combination with the low DIS of my PCM, the idle of the car while out of gear was pretty rough, but liveable. In gear, the idle was, of course, even worse and was sometimes on the verge of stalling which it did a few times while I was backing slowly out of our driveway. Worse than the very rough idle in gear was the PCM "searching" for the proper idle speed. This is commonly called surging and, in my case, the idle would go up and down between about 400 to 550 rpm and never settle on one speed. This was VERY aggravating. The solution to all of this, of course, was to just raise the idle speed by 100 rpm or so, but that's not an easy task with these cars. The days of a few turns of a screwdriver are long gone. Following the advise of others, I drilled out the hole found in the throttle body blade 1/64" at a time, trying to improve the idle quality. I ended up with a 7/32" hole and this did improve things, but not considerably. I finally altered the idle position by glueing a .025" thick spacer under the idle stop plate. This keeps the throttle from going all the way down and raised my idle speed about 50 rpm which is all I needed. Believe it or not, but that 50 rpm has made all the difference in the world. Incredibly, it now idles out of gear BETTER than it did with the stock cam. In gear, the idle is still a little rough, but nothing really objectionable and problem of surging and/or stalling are completely gone. Yahoo!
Steve
Posts: 517 | From: Hazle Township, PA | Registered: May 2000
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quote:Originally posted by Hawkeye: sounds cool - now open her up and let us know how it feels - SOTP.
Hawkeye.
Hey, Hawkeye! Well, I can tell you, she is much stronger, especially in the mid-range. The car just pulls so much harder now right to redline and doesn't seem to flatten out. The car even got a little squirrelly on me when shifting between 2nd and 3rd at WOT which is a first, so there is a definite power increase. I can't wait to get to the drag strip! Of course, it has to stop SNOWING for me to do that!!! We're in the midst of another dang snowstorm even as I type. Will it ever end!?
[This message has been edited by XTrooper (edited 22 February 2001).]
Posts: 517 | From: Hazle Township, PA | Registered: May 2000
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posted
Thanks for the detailed information Steve. It is very clear. I really can't wait to see her go at Englishtown. Now be a good friend and keep that white stuff down there where it will melt faster!! Happy driving!
Posts: 5946 | From: Litchfield, NH, USA | Registered: Feb 2000
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quote:Originally posted by DaddySS: Sounds great, I am very happy that it worked out (you worked it out!) and envious of your new performance! Congrats!
Thanks, DaddySS!
Dan,
We are getting buried here! There's at least six inches on the ground as I type and it's supposed to keep snowing till midnight. Aaarrrgggghhhh! Thank God I got to run the SS a bit after I got the cam installed. If not, I'd be dying here now!
Steve
Posts: 517 | From: Hazle Township, PA | Registered: May 2000
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You WOULD ask that!
We're in the midst of another dang snowstorm even as I type. Will it ever end!?
