1st: TFI distributors suck donkey balls. Rotors and caps wear out
TFI modules go bad, pick-ups go bad. Switching to coil packs gives
you MUCH better spark control and timing input.
The AEM has issues with timing errors with TFI distributors.
It reads the timing so accurately that the small errors it gets throw it off.
Really only seems to like factory Motorcraft distributors. Mine hated my
MSD billet distributor.
There is a sticky on AEM forum regarding this
I would plug-n-play the AEM with your stock ignition at first just to
get it running. But upgrading to the EPM module and coil packs will pay
off in the long run.
EPM wasnt out when I did my coil pack install, So I used modified Explorer
cam and crank sensors on mine. Junkyard parts. Took lot of head scratching
to make work, but the parts were dirt cheap.
got a question on timing for EPM and LS1/2 coil packs. What timing light is everyone using? I want to buy one that work with both the factory ignition and later for my LS2 stuff.