So over the last several months I have been trying to diagnose the voltage drop that I'm experiencing at full operating temp at idle cruise. I'm currently running fic bluemax 1800cc injectors and they will only stay happy between 12.6 to approximately 14 volts. It becomes a serious problem when the voltage drops below 12.6 at wot. I originally started of by checking all my grounds. I have a 2ga ground strap from the head to the chassis. The battery has been relocated to the trunk and has 0ga ground strap from the battery to the chassis there. I decided to run a 4ga ground from the alternator to the block and additional 4ga power wire from the front fuse block main power source to the power distribution block that I have in the engine bay. I also replaced the 120amp ebay alternator for the 160amp alternator from supra store. Those 2 things seem to help but only mask the problem. The engine also has a brand new wiring harness. At this point I'm open to any possible ideas or suggestions. Has anyone had a similar problem?