LT1-LT4 Modifications 1993-97 Gen II Small Block V8

idle issues

Old Aug 14, 2007 | 11:43 PM
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Default idle issues

i got a pcm for less tune recently and the idle will fall to about 600 rpm(on gauge) and feel like it wants to die when i come to a stop for a few seconds then it bumps up to 1000 rpm and idles steady until i start and stop again. the ses light came on the other day and showed p1035 bank 1 sensor 1, so i assumed that was the cause of my idle issue. i replaced the o2 sensor with a new ac delco unit and cleared the code but my idle issue remains. any ideas or common culprits? Thanks.
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Old Aug 15, 2007 | 03:56 PM
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Originally Posted by 97blackz28
i got a pcm for less tune recently and the idle will fall to about 600 rpm(on gauge) and feel like it wants to die when i come to a stop for a few seconds then it bumps up to 1000 rpm and idles steady until i start and stop again. the ses light came on the other day and showed p1035 bank 1 sensor 1, so i assumed that was the cause of my idle issue. i replaced the o2 sensor with a new ac delco unit and cleared the code but my idle issue remains. any ideas or common culprits? Thanks.
Sounds like your IAC isnt responding fast enough. You can test it with a multimeter, and each set of terminals should show 40-80 ohms, with the opposite ones open. Either AB-CD or AC-BD, currently not sure.

What are the IAC counts on warm idle? It may just be at too far of an extreme, and it takes too long to open to a point where it can compensate the quickly closing blades. In that case, you may just need to drill the IAC bleed hole in your TB to give the IAC more control over your idle and balance the counts. BBK's do not come with them, and it will really help the idle of a cammed car. Just an 11/64" hole right in the stock location.

The bleed hole/IAC isolation helped a TON on my Z.
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