proelky

iTrader: (13)

Gentlemen....

I swapped an LY6 into an 08 Avalanche using the stock 4L60E trans and have ran into a tuning hurdle. Is the LY5 and LY6 throttle bodies the same?

While tuning (HP Tuners) under WOT the throttle body blade fluctuates between 55%-88% and we've not be able to solve the issue. We verified pin locations, and other than locating an LY5 TB not sure what to do.

Any suggestions?

proelky

iTrader: (13)

Apparently when swapping from an LY5 to LY6 with dbw it requires the trans, pedal, and tb signal to match. LY5 tb solved the issue.

2007chevy5.3l

iTrader: (21)

Both engines should have the exact same TB's. I have a friend that did it and it was a direct swap. Maybe you have a bad connection somewhere??

proelky

iTrader: (13)

So at this point I've changed and or verified the following: New fuel pump, coils, wires, spark plugs, and injectors. Luckily we had a spare engine laying around. Anyhow, the cam is a comp 54-426-11 222/224 566/568 on a 112. The issue is the engine is surging on startup....and at random. Are the sensors the same between LY5 and LY6? Is this issue strictly tune?