Hope someone can help. i just added VTEC to my LS block and for some reason it wont run right at full throttle. Driving normal gradually giving it gas is o.k., the VTEC kicks in but at 6000rpm it boggs real bad and runs like hell. From a stop if I punch it, it will also bogg and go slow as hell. We've changed the cams, throttle body, fuel filter, fuel pump, fuel regulator, tried Stock ECU, Skunk2 ECU, and my chipped ECU and no fix, Timing is set at TDC, and I'm running out of Ideas. My next guess is to change the intake manifold. I hope someone can help. Thanks

 

wow, bump for an answer


good luck man...

 

are you using a gsr manifold? if you are, what ecu are you using? maybe the secondaries are not opening.
bad tuning? did nothing change when you switched ecus?

 

did you check the ignition? i had an msd setup that was constantly givin me trouble
wires shortin out or somethin i took out the msd setup and put stock coil back in it runs great