Rough/high idle

434 Views 5 Replies 3 Participants Last post by BIGBODY9SIX, 5 d ago

Big Jack

Discussion Starter · 1 mo ago

Hi guys, about a month ago, my LT1 started idling rough once warmed up (but idles smooth cold) Smooths out when I give it gas. "check/service engine" light came on when it first happened, but went out on it's own. There's no codes present when I check through the automatic climate control panel. I've tried cleaning the throttle body and idle air control valve. MAF is still clean from last time I cleaned it years ago.
What could be causing this?
Also, after cleaning the throttle body (probably for the first time ever), idle speed is quite high. Does the PCM "re-learn" the idle speed, or do I have to back out the screw that the throttle shaft stop rests on?
Thanks

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95wagon

· #2 · 1 mo ago

A stock car you should never be touching the idle stop screw.
Re set as I recall
depress accelerator pedal slightly, start and run engine for 5 seconds, then turn ignition off for ten seconds."

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Big Jack

Discussion Starter · #3 · 10 d ago

UPDATE: check engine light came on. Codes indicated were 13 (left o2 sensor circuit open) and 44 (left o2 sensor lean condition detected). I pulled both o2 sensors (left one was blacker than right) and switched them. After switching, got code 64 (right o2 sensor lean condition detected).
I'm thinking it's a bad o2 sensor, but I hope this isn't a chicken vs egg thing.

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BIGBODY9SIX

· #4 · 5 d ago

I got 2 brand new acdelco 02 sensors I never used if you looking to buy gm ones

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Big Jack

Discussion Starter · #5 · 5 d ago

BIGBODY9SIX said:
I got 2 brand new acdelco 02 sensors I never used if you looking to buy gm ones

I just got a pair of Bosch's delivered... Then I read some not so great reviews about Bosch o2 sensors. Luckily they're from Amazon prime, so if I have any problems with them I'm sending them back and will buy your Delco's

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BIGBODY9SIX

· #6 · 5 d ago

Yea I dont trust those I always get gm quality stuff but just lmk can give a deal both shipped

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