LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Lt1 Idle help!

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Old Jul 18, 2012 | 05:24 PM
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Default Lt1 Idle help!

I dont you where or if i could post it here, but doesnt hurt to try. So, i recently bout a 1994 z28 6 speed with 100,000 miles. It idles at 2000 rpms, and cant figure out why. Some of my friends say its a vacuum leak, but the way it idles i doubt it. It says at 2000 rpms, doesnt go up or down just stay there. ( when i turn it on) I noticed that it doesnt have a gasket for the top of the throttle body (cover gasket?) could it be that? Also, the gasket for the throttle body looks kind of torn, so im not sure if it can be that also.
Thanks for all who can give info.
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Old Jul 18, 2012 | 08:55 PM
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Seriously, it is hard to understand what ur saying/asking but.. Does it have a service engine light ? (ses). If so, Scan for codes.
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Old Jul 18, 2012 | 09:10 PM
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Make sure your throttle cables not stuck open alittle for 1, and 2 yes get a scan tool or go to autozone if your check engine light is on. Thats a start, probably a bad sensor
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Old Jul 18, 2012 | 09:49 PM
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Ill try to re-write it again. I recently bought a 1994 Camaro M6 with 100,000 miles on it. It has a very high idle, it stays 2000 Rpms, it doesnt go up or down, just stays there. It seems it doesnt have a cover gasket on the throttle body. ( changed it today, it wasnt it) Also, the throttle body gasket was torn, i changed it today but that wasnt the problem either. Ive inspected the hoses but they all seem to be fine. But, everyone keeps telling me it has a vacuum hose leak. But, it doesnt seem that it could be a hose, only because the idle stays ar 2000 Rpms, when everyone says the idle is supposed to be low? Could it be anything else? Is there anything i can do sort of locate where the problem is coming from?
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Old Jul 18, 2012 | 09:53 PM
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Originally Posted by cprmn14
Make sure your throttle cables not stuck open alittle for 1, and 2 yes get a scan tool or go to autozone if your check engine light is on. Thats a start, probably a bad sensor
I've checked those and they where fine. I checked the IAC and it looked to be fine also, but soon will replace anyways. Ive also checked the tps, and it was fine. Autozone was no help, or pepboys etc. So, im guessing im going to have to buy the tool.
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Old Jul 18, 2012 | 10:24 PM
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When u say u have checked these things and they all seem to be fine, how are u checking them? Live datastream? How are u checking for vaccum leaks?
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Old Jul 19, 2012 | 12:30 AM
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Originally Posted by FAD2BLK93
When u say u have checked these things and they all seem to be fine, how are u checking them? Live datastream? How are u checking for vaccum leaks?
Well, its because ive replaced them. For vacuum leaks someone recommended that i use carb cleaner, to spray it around the throttle, but to say the truth im not sure if im doing it rite. They said if it has a leak that it would idle up??? so im not sure.
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Old Jul 19, 2012 | 01:02 AM
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I'd say start at the IAC. You may also try to unplug the MAF and run it in SD mode to rule that out just in case, but I doubt that's the culprit.

If you've got a vacuum leak, spraying carb cleaner should make a noticeable difference in the idle, from my experience anyway.

Another thing that's a free fix (probably not the problem) but wouldn't hurt to do is to clean the TB thoroughly.

Sorry its not a lot of help, just throwing a couple of ideas out there.

EDIT/ If its a 93, I guess you can ditch the MAF idea, haha.
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Old Jul 19, 2012 | 10:49 AM
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I worked on my car and my buddy busted the IAC valve, mine did the same exact thing when I turned it over. It just jumped up to 2k and stayed there. Thats my first and only guess on that since you checked the lines and cable. Take the IAC and look at the connections.
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Old Jul 19, 2012 | 12:55 PM
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Originally Posted by 97Z28LT1
I'd say start at the IAC. You may also try to unplug the MAF and run it in SD mode to rule that out just in case, but I doubt that's the culprit.

If you've got a vacuum leak, spraying carb cleaner should make a noticeable difference in the idle, from my experience anyway.

Another thing that's a free fix (probably not the problem) but wouldn't hurt to do is to clean the TB thoroughly.

Sorry its not a lot of help, just throwing a couple of ideas out there.

EDIT/ If its a 93, I guess you can ditch the MAF idea, haha.
I will try that out again, doesnt hurt to try.

I tried that method but to me it feels im doing it wrong, but i will try again.

Yesterday i throughlt cleaned the TB, just made my car run smoother. lol

No problem, but something then nothing rite.

Thanks for the ideas/help.
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Old Jul 19, 2012 | 12:57 PM
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Originally Posted by FormyLtX
I worked on my car and my buddy busted the IAC valve, mine did the same exact thing when I turned it over. It just jumped up to 2k and stayed there. Thats my first and only guess on that since you checked the lines and cable. Take the IAC and look at the connections.
I pulled mine out when i took off the TB, it looked fine, but then again thats just me thinkg. Im going to replace it. Hopefully thats the problem, worst case is just to change all the vacuum hoses. Hopefully that will be the solution.
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Old Jul 19, 2012 | 11:14 PM
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TTT.

Thanks.
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Old Jul 19, 2012 | 11:33 PM
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Get a cheap LT1 cover with a gasket to fix that & if something "looks" good It can Test bad A leaking intake will do some funny **** Pull the intake & reseal it @ 100k its leakin oil anyway lol Be carefull not to break the oil pressure sensor If the TB gasket is torn replace that too Also check for bare wires My little cousin had a 95 Z28 & it started runnin like **** so he had me look It had a chipmunk livin in there that liked chewin on wires Fixed all that & it ran like a raped ape again Its idle wasnt right either When you say you cleaned the TB did you use carb cleaner & compressed air too Plus remove everything off of it LOTS of passages in there Hope this helps
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Old Jul 23, 2012 | 04:57 PM
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TTT.
Bump.
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Old Jul 23, 2012 | 05:50 PM
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Hopefully this helps. Doubt it. What the car has new. New spark plugs, wires, opti spark, Coil pack?, new TB Gakets, New fuel pump an filter, All new oils, transmission, Diff etc. The opti spark wasnt installed by me, could that be an issue? Why it idles so high. It feels like someone just has there foot on the pedal.
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