crank variation relearn - The 1947 - Present Chevrolet & GMC Truck Message Board Network

LeesTruk · 03-21-2015, 05:32 PM

After the LS engine is installed, harness reworked and PCM reflashed by whatever vendor is chosen, is it necessary to perform a crankshaft variation relearn, and if so, does a Tech2 need to be used, or is there another way to do it? Thanks

Lee

BR3W CITY · 03-21-2015, 06:42 PM

Depends how far out of sync the cam and crank sensors end up, which will depend on the cam. Most of the time its not "needed". Forcing a crank relearn is something to consider if it wont't fire, or throws repeated crank and misfire MIL's, without ever running. Sometimes people who have tripped VATS reported having to do it after, but thats only speculation.

03-21-2015, 05:32 PM	#1
LeesTruk Registered User Join Date: Mar 2015 Location: Manchester, CT Posts: 429	crank variation relearn After the LS engine is installed, harness reworked and PCM reflashed by whatever vendor is chosen, is it necessary to perform a crankshaft variation relearn, and if so, does a Tech2 need to be used, or is there another way to do it? Thanks Lee

03-21-2015, 06:42 PM	#2
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: crank variation relearn Depends how far out of sync the cam and crank sensors end up, which will depend on the cam. Most of the time its not "needed". Forcing a crank relearn is something to consider if it wont't fire, or throws repeated crank and misfire MIL's, without ever running. Sometimes people who have tripped VATS reported having to do it after, but thats only speculation. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD



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