C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Idle problem

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Old Sep 19, 2025 | 06:42 PM
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Default Idle problem

Recently, my 85 Corvette was idling at about 600 but surging up and down and sometimes quit. I replaced the TPS and IAC sensors and now engine idles at a constant 1400 and won’t go back to 600. I moved the tps a little back and forth with just a little change. I have not disconnected the battery yet and then connected. Will that help at alL TO SET idle ? What else should i try. Thanks for any info .
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Old Sep 19, 2025 | 08:08 PM
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FWIW my 88 was doing similiar. An ECM swap fixed it. But, i also coukdnt get the car into diagnostic mode. Have you tried to pull codes from it?
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Old Sep 19, 2025 | 08:35 PM
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