Bad idle after swap

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Aug 31, 2014 | 03:39 PM

badtransam97

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Bad idle after swap

Just finished the T56-TH350 swap, and the car is not idling very well at all. It will do pretty good in park and neutral, but not in gear. It starts surging pretty bad and dies. Car has a 4.10 gear, tsunami cam, etc...and has been tuned for the cam before the swap and has been idling and running perfect. I am wondering if it could be a little more drag since it had a converter to spin, and or maybe the lack of signal from the VSS, since it also threw a SES light bc of the VSS I am assuming. Havent been able to get back to the tuner to scan it. Any ideas?? Thanks!

Aug 31, 2014 | 04:28 PM

01ssreda4

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From: Turnin' Wrenches Infractions: 005

Completely normal. Changing rotating masses severely effects idle!

Aug 31, 2014 | 04:44 PM

badtransam97

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Would you recommend just an idle change, or is their something else to check in the tune? I personally do not tune the car, but I can pass the info to the tuner. Thanks

Sep 1, 2014 | 11:11 AM

mrvedit

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From: Ann Arbor, MI

Quote:

Originally Posted by badtransam97

Would you recommend just an idle change, or is their something else to check in the tune? I personally do not tune the car, but I can pass the info to the tuner. Thanks

Idle tuning is not just turning an electronic "idle screw". Here is the detailed procedure I follow after any major changes that upset the idle:

http://www.hptuners.com/forum/showth...de-(w-pictures)

There are idle air flow tables, idle ignition advance tables for both Park/Neutral and Drive. Once set, these tables should then be blended into the main VE and ignition advance tables. I suspect many tuners take shortcuts, but if you want it perfect, that is the multi-hour procedure.