Which TB for LS3 crate engine
02-03-2011, 04:38 PM
#1
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Which TB for LS3 crate engine I have a LS376/480 and have fitted the later type TB with the brass plate. I'm having idle problems with it and have read it should have the older LS2/3 TB part number 12570790. Is this likely to fix my problem? I'm considering buying HP Tuners to have a go at setting up the idle, and tune generally. I have the GM ECU/harness kit for that engine. Do I buy HP Tuners, the earlier TB, or both? Help would be appreciated guys. THe installation is great and nearly done, but I'm fed up with how its running.
Mark
Mark
02-03-2011, 06:28 PM
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What year is the PCM and from what vehicle? If you have an earlier than 08 PCM, I don't believe or at least haven't seen anyone successfully tweak the tune to make that TB work.
02-05-2011, 05:31 PM
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I got hold of a 12570790 throttle body today and fitted it. Its cured one problem - the MIL is now so I guess the later TB was incompatible with the ECU. The engine seems to run better but the idle problem is still there - dying on return to idle. Seems like its time for HP Tuners next...
02-06-2011, 09:16 AM
#6
why did you ditch the TB that cam on the crateengine?
02-06-2011, 03:33 PM
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The engine didn't come with a TB. Its a LS3 crate engine originating from Australia. I bought the later type TB which was throwing up a DTC. I have the earlier type now with the silver plate and the DTC is gone but the bad idle remains. I have read lots of stories on here and HP Tuners forum of the LS376/480 engine not idling right with the stock GM tune.
02-07-2011, 02:25 PM
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You'll probably just need to update the tune in that PCM. What tuning software are you running? Depending on if that 06 CTS-V ran a 90mm TB, you may need to change the ETC Throttle Area Conversion. Also, adjusting Air Flow will help it idle, it did mine 
02-08-2011, 10:41 AM
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