| IAC valve 87 vs 91 tuning issues |
Subject: IAC valve 87 vs 91 tuning issues by Woodstock on 2010/3/3 1:41:45 I am helping a friend tuning his 87 with LT4 hotcam, BBK TB, Trickflow heads and Lingenfelter intake. He always had trouble shifting into gear (TH700) with stock converter. Now I had enough of "160-full open" IAC counts and send him my spare 91 IAC. Previously he used both of his 87 IACs. Sure enough now the IAC works as it should, but the tune still needs some work. Now the question. Could it be, that using the 89 ARAP code could have ill effects on the 87 IAC, but working correctly with the 91. I believe 88 was an IAC number change, but was the IAC really a different animal? Usually I am not a believer in GMs part number system, but this one has left me stumbled. |
