LT1 idle

[maroman88]

how do i adjust the idle on an LT1? mines a little high, about 1k when stopped in drive and about 1400-1600 when in park

[Tru2Chevy]

I believe it's all done in the computer.....might want to look for reasons for the high idle.

- Justin

[The Fixer]

Mike, check the free stuff first. Look for obvious vacuum leaks or a binding throttlebody.The F-body LT1 has a plastic cover over where the throttle/TV cables go into the TB. It might be binding up inside there; I remember that happening to me once or twice after I put that cover on my old Impala SS.

[ar0ck]

If you took your Elbow off double check the seal around the throttle body. Those stupid elbows like to rip very easily.

[ins0mnia24]

check and clean your i.a.c. it might be stuck open

[maroman88]

so far alex is the winner lol, that elbow has 2 pretty good rips on the bottom, and that stupid air silencer snorkel lookin things is loose

[Tru2Chevy]

http://cgi.ebay.com/ebaymotors/NEW-GM-93-97-Camaro-Z28-LT1-1LE-Intake-Bellows-Duct_W0QQcmdZViewItemQQcategoryZ43946QQihZ012QQite mZ220158564456QQrdZ1QQsspagenameZWDVW

Go find this used.....

- Justin

[maroman88]

bought a powder coated aluminum elbow :evil:

but i was lookin for one of them without the silencer tube

[Tru2Chevy]

bought a powder coated aluminum elbow :evil:

but i was lookin for one of them without the silencer tube

Powder coated, or ceramic coated? If powder....lots of heat soak.

- Justin

[maroman88]

new elbow is on, still idles high. i got the OBD2 cable and plugged in my scanner.
the TPS reads 0.80, thru some research it looks liek it should be 0.69ish.
on the TPI's u could adjust it by losening the bolts and sliding the TPS sensor up or down. on the LT1 there is no way to do this without drilling out the holes on the sensor. whats the proper way
??

[bubba428]

there should be a set screw on the TB....you see a tang that sticks to limit how far the linkage moves




EDIT: like so

http://img2.putfile.com/thumb/10/29112495278.jpg (http://www.putfile.com/pic.php?img=6898424)

[maroman88]

yea i kinda wanted to stay away from moving that screw, unless it can come loose on its own over time, then that could be a solution

[bubba428]

well if theres no SES light, no vacuum leaks, that might just be it...

[deadtrend1]

well if theres no SES light, no vacuum leaks, that might just be it...

very doubtfull. That screw just doesnt come loose. And If i remember on my TPI car, you need to knock out a hole to get to the screw.

[maroman88]

very doubtfull. That screw just doesnt come loose. And If i remember on my TPI car, you need to knock out a hole to get to the screw.

exactly wat i thought, my TPI is like that.

i do have one code that keeps popping up but its for something with the EGR system and only happens when cruising at a constant speed for a few minutes. the car idles to high all the time so i think its unrelated

[Tru2Chevy]

You never know.....a bad EGR can cause all kinds of weird issues.

- Justin

[BonzoHansen]

If the TPS is high, perhaps the TPS needs adjustment/is bad?

[maroman88]

i drilled out the holes on the TPS and adjusted it from 8.0 to 6.0, no change
i checked on the throttle blade screw and theres no cover on LT1's so i moved it a little and it was pretty loose, not hard to turn so i adjusted the idel down to about 900rpm in park. took it for a test drive, idled at about 700rpm when stopped and in gear. checked the TPS with my scanner once again and now the TPS read .54 so i bumped that back up to .60 and all seems pretty good

its code 32 EGR failure i get while cruising at a steady speed, then the light goes off and the code goes to the code history bank on the scanner

[WildBillyT]

Did you check your IAC valve??

[maroman88]

i tired, but i dont have a repair manual yet and could only see one bolt holding it in and didnt wanna force it off. its reading 0 steps when at idle on my scanner, with 0% throttle angle and TPS at .60

[WildBillyT]

i tired, but i dont have a repair manual yet and could only see one bolt holding it in and didnt wanna force it off. its reading 0 steps when at idle on my scanner, with 0% throttle angle and TPS at .60

Well, depending on the style, if you take it out and push the plunger all the way in (gently) the car should fire up with a really high idle and level off. If it doesn't level off then I'd say it's shot.

[ins0mnia24]

The I.a.c. is what supplies your engine with air when the throttle isnt engaged or when you arent giving the engine gas and the throttle blade is closed...
Like when you are in Park,Sitting while stopped, coasting ect...

I would clean the I.A.C. Passages with carb or throttle body cleaner
Then clean the I.A.C. Pintle
After you clean it your Pintle should be around an 1 1/8th from the valve to the tip of the Pintle..
When you reinstall it the Computer will reset it if it is working properly..

That is your cheap fix if that doesnt work then your idle issue's are realted to your EGR problem

[IROCZBeast]

I had a similair problem back in the day and it resulted because of a bad a.i.r. pump and or a clogged cat. Went out and bought non-emission pacesetter lt's with an off-road y-pipe and never had the problem again.