I have been looking over my LT1 Edit logfiles and noticed that under WOT the RPM will sometimes drop 100 or 200 rpm then jump back up again. I thought it was related to when the PCM pulls timing, but it happens even when there is no timing retard. Is this normal? Do others see this in their logs? Below is an example from my log. Any ideas?

22:22:13 4825
22:22:13 4975
22:22:13 5100
22:22:13 4875
22:22:13 5025
22:22:13 5275
22:22:14 5300
22:22:14 5125
22:22:14 5475
22:22:14 5275
22:22:14 5350
22:22:14 5575
22:22:14 5350
22:22:14 5475

Thanks

 

Your ignition would be the first place to look on this, it can be a number of things really, but the first ones that come to mind are the coil going bad or the ecm not getting a good signal from the opti.

 

I would say its the ignition coil. I used to have a 94 Trans Am, and it sputtered at WOT, and the coil fixed it. I bought an MSD Blaster, it bolts up the same as the OE unit, and has more output.