crazy idle.....dont know what to do

**jmatt07** · 04-27-2009, 07:56 AM

ok ive been havin a high idle since i did h/c/i lt's ory, 42# injectors, 85mm tb......i cannot figure out this idle problem. i got a mail order tune done. i put in new 02 sensors, got the codes cleared, got a shop to run scanner on it, adjusted the throttle body. the only codes pulled by the scanner was po507 and i cant remember the other one but it was a reverse solenoid or something. the mechanic said that one was probably bc of the skipshift. i checked all vaccuum lines and they look good. it was at a stop idling at 1400 but when i was rolling it would be at 2200 it wouldnt go down until about 5 seconds after i stop but after today. i checked the throttle body and adjusted it and took out iac sensor to look at it and i reset pcm and was gonna do an idle relearn but as soon as i started it up it idled at 2400 and wouldnt go down. after about 5 minutes i shut it off. does anyone have any idea or can help?

i couldnt find a leak but the only thing i can think is the intake isnt flush or something. it looks like it is but if i cant figure it out i will probably take intake off. i got the bbk intake by the way and they said that i didnt need the ls6 coolant lines that go underneath it, so im wondering if maybe i do need it.

**sunsetorangess** · 04-27-2009, 08:00 AM

Dis-connect the IAC harness from the sensor and see what the idle is at.
J

**jmatt07** · 04-28-2009, 05:28 AM

ok well i figured out the problem.........sort of........i retorqued my intake bolts and the idle was perfect. i was really happy.....but after i drove it for a acouple hours the high idle returned and i torqued them down again. well it fixed it again and it worked the rest of the day but this morning it the idle is starting to go up again. are my gaskets bad? or are the bolts just keep loosening? what can i do about it? Thanks

**shady milkman** · 04-28-2009, 05:40 AM

are you torqueing them back to spec? what intake are you using ? fast ? if so did you get the right length bolts..if its a ls6..i would make sure that you put the intake on right..with the gaskets..some times if you slide the intake in..it a gasket can catch on the intake port of the heads..and pop out a little..so when your running..everything heats up..and the rubber expands..making the leak more prevelent..you torque them down..and seals the intake a little tighter..and it helps seals the misplaced intake gasket..but as the car cools..the gasket shrinks a little..and causes the same issue.....so take the intake off..and when reinstalling it..try to drop in down into place instead of sliding ...and replace your gaskets

**jmatt07** · 04-28-2009, 02:31 PM

i have the bbk intake. does anyone know if the torque specs are higher on those than on a stock intake? it came with new bolts and i used them but i torqued them to stock specs. i did reuse the old gaskets so i might have to replace those. i also still have the ls1 coolant lines but that doesnt explain why when i tighten it, it will run right for about a day and then go back.

**Dr.Crash** · 04-28-2009, 03:07 PM

i would start looking for a vacume leak. did you do the install your self?

**0rion** · 04-28-2009, 05:45 PM

I'm not sure on the BBK intakes but I would imagine that you could switch to the ls6 coolant crossover and rear coolant plugs. That's what I would do then re-torque the bolts down using blue loctite on them. Those lines under there *could* be keeping the intake from seating all the way down and it's helping those bolts back off.

**tbias** · 05-04-2009, 04:40 PM

the wiring harness for your knock sensors can cause you clearance issues as well. Right where the 2 lines join (center of the intake)the factory puts alot of tape on them. Also remove the plastic clips that hold it on the coolant pipe. lol

**jmatt07** · 05-05-2009, 05:04 AM

ya we took off those plastic clips on the knock sensor harness when we put the intake on. the thing is weird. now the bolts arent loosening up but it still idles high sometimes like they loosened up but then it will start idling right. it goes back in forth. either idles good or idles like there is a vaccuum leak. i dont want to keep tightening those bolts bc i dont want to strip threads or anything. i know the stock torque specs are 89 inch pounds. right now i have them torqued at like 120 inch pounds. i just dont understand what would make it idle real high sometimes and then idle fine without me even doing anything.