another 2005 5.3l question

mrspeed64 · March 26, 2005

Does anybody know what GM did to the 2005 5.3l iron block to make it a "flex fuel" motor. Different computer program or is there more?? These motors are in the 2005 ls 4x4 ecsb models. The regular 5.3l iron block is available on the 8' bed. Anybody have one of these "flex fuel" motors and how are they?

Nick99Chevy · March 26, 2005

Does anybody know what GM did to the 2005 5.3l iron block to make it a "flex fuel" motor. Different computer program or is there more?? These motors are in the 2005 ls 4x4 ecsb models. The regular 5.3l iron block is available on the 8' bed. Anybody have one of these "flex fuel" motors and how are they?

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Are you talking about the 5.3 HO? It only comes in Ext cab 4x4's but it's not the same as the flex fuel. It has LS6 heads, aluminum block and different tuning.

Jeff1 · March 27, 2005

Does anybody know what GM did to the 2005 5.3l iron block to make it a "flex fuel" motor. Different computer program or is there more?? These motors are in the 2005 ls 4x4 ecsb models. The regular 5.3l iron block is available on the 8' bed. Anybody have one of these "flex fuel" motors and how are they?

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We have the 5.3 flex fuel motor in our 04 Yukon, not sure what makes it different though.

willieboy · March 27, 2005

IIRC, the differences are computer software, injectors, and fuel tank sensors. The fuel tank sensors check the fuel density to determine the amount of ethanol in the fuel, and adjust the fuel maps to coincide with the appropriate level of ethanol.

redvett · March 27, 2005

Does anybody know what GM did to the 2005 5.3l iron block to make it a "flex fuel" motor. Different computer program or is there more?? These motors are in the 2005 ls 4x4 ecsb models. The regular 5.3l iron block is available on the 8' bed. Anybody have one of these "flex fuel" motors and how are they?

The flex-fuel is a combination of PCM calibrations,the entire fuel system including special sensors in the fuel lines all designed to run on different fuels. Thats whey it costs over $300 more.