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ENGINE running bad, HIGH IDLE.

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Old Aug 25, 2008 | 10:29 PM
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Default ENGINE running bad, HIGH IDLE.

my idle is very high, my engine was ran through water a few weeks ago and it all got fixxered, but theres a couple things i need to replace and idk what they are..

my car starts up at 2500rpm..than goes back down to about 1500, which is still very high, and when i put it in drive it will idle at 900-1100....my car will basically drive itself to about 40. my car only runs good when i have the bottom two 02 sensors unplugged. if they are plugged in, it will run very rich. from what ive noticed, it seems like my car is getting too much oxygen...but idk. help me please.

thank you
Evan
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Old Aug 26, 2008 | 08:34 AM
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Does unplugging the O2 sensors fix all of the problems or are you saying it would be even worse if you had them plugged in?
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Old Aug 26, 2008 | 11:14 AM
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it would be alot worse if i plugged them in, with them plugged in my car boggs up, spits out gas, and when i WOT it will basically stop running, also it will pull stupid random codes like MAF which is new, and engine running lean which i think means too much gas, so thats understandable.
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Old Aug 26, 2008 | 11:42 AM
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Check the sensor fuse?
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Old Aug 26, 2008 | 01:13 PM
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that might be one...i will check the fuses, i doubt thats it, but theres always a chance.
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Old Aug 26, 2008 | 01:18 PM
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i know on the ls1's, the maf and o2's are on the same circuit with the skip shift solenoids too. when that pops, **** hits the fan....
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Old Aug 26, 2008 | 01:34 PM
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what do you mean circuit? in the cpm? cuz nothing on my cpm is burned or anything, its just kinda corroded and what not..
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Old Aug 26, 2008 | 09:55 PM
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same circuit means under the same fuse
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Old Aug 26, 2008 | 11:36 PM
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mkay..so its inside the cpu unit right? i havent taken it completely apart yet..but i will if thats the last resort.
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Old Aug 27, 2008 | 11:00 AM
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Originally Posted by KadinZ
mkay..so its inside the cpu unit right? i havent taken it completely apart yet..but i will if thats the last resort.
There is a fuse panel in the engine compartment. That's where you'll find the sensor fuse.

Also, it's important that the large PCM plugs are well connected. Clean and dry the connections and reassemble, making sure the thin seals are positioned correctly and in good condition.
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Old Aug 27, 2008 | 11:17 AM
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WELL, I DID DO THAT SONDAY, CLEANED EVERYTHING NICE AND GOOD, MADE SURE EVERYTHING WAS CONNECTED good too, but i believe if its anything...the cpu is damaged from having water in it for a month. i will keep everyone posted with what ive done and possibly with more questions on what to do next.


sry bout caps, dont want to re-type
thx, Evan
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Old Aug 27, 2008 | 11:58 AM
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could be a bad computer. If you get another one to try, make sure it's the exact same p/n, has to be from a car with the same engine and transmission and everything, and sometimes it has to be the same year as well.
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Old Aug 27, 2008 | 01:47 PM
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well, most likely im going to get it brand new from autozone..its only 125$ and i havent checked gm yet, do they need to program it or should it already be programmed?
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Old Aug 27, 2008 | 02:06 PM
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Default running badly

First off there are no fuses for the 02 sensers, have you pulled the codes? AutoZone will do this free of charge- have any lean codes? could be a simple vacuum leak- I had the same issue with erratic idle seemed ok going down the road- A/Z said poss MAF- had an extra and swapped it-more codes. turned out all it was the rubber line between PCV and the intake - its common that they deteriorate and leak unmetered air and the ecm cant adjust enough to make it run right - check the basics first especially before you throw a ECM that has to be programmed for your car at it mine was about .50c of fuel line to fix little 3" piece. Worst thing is I know these go bad all the time. It comes with part of PCV line assy about 50$ at the stealership.
Thats why shops charge to diagnose a vehicle - usually a diagnostic is 90% of the work to fix a vehicle - hope this helps you
my bad didnt see you were LT1, why did you post this in :LS1-LS2-LS3-LS6-LS7 PERFORMANCE " ??

Last edited by zman1969; Aug 27, 2008 at 04:52 PM. Reason: was thinking LS engine
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Old Aug 27, 2008 | 03:02 PM
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well, heres something...i have something called a 'breather' and i just replaced it, theres a hose coming off of my intake manifold and to the back of my engine where it plugs into this 'breather' and i always thought that was the pcv valve's area, but idk...maybe its the same thing as a pcv valve, just better or summin?
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Old Aug 27, 2008 | 03:04 PM
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The PCV is concealed between 2 hoses in that line, and if you have a line running to the intake manifold, it's not a breather. A breather is just a filter plugged into the hole that vents directly out.
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Old Aug 27, 2008 | 03:22 PM
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i might need pictures, the guy who had the car before moded it, and yeah...idk if he took things off, bypassed stuff idk.
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Old Aug 27, 2008 | 03:34 PM
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OOH, something i have to tell you guys....i saw under my intake theres this small like...1/8" diameter lookin pipe with a cone-lookin tip, it looks like it should have a hose on it leading somewhere, but idk where that hose goes to...may someone explain to me where this hose possibly goes? it comes off about 1.5" off the bottom of the manifold, just below the air intake pipe/plastic piece.
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Old Aug 27, 2008 | 03:35 PM
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http://www.installuniversity.com/ins...sity/index.htm

Edit: Oh, LT1. I'm not sure if it's the same. You can check. I've never had an LT1.
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Old Aug 27, 2008 | 03:38 PM
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^^hate you^^

thx for trying tho
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