For part 1 of this writeup, go here: http://forums.stangnet.com/showthread.php?t=593406 it will explain alot about the custom EFI system I chose to use (MegaSquirt) and my goals. Part 5 is going to be all about tuning the megasquirt for fuel delivery. Having Megasquirt control ignition will be part 6. Part5 – Tuning Tuning was more difficult than I expected it to be in some ways, while easier in others. It was more difficult because this is when any mistakes you made along the way will start to show, or any problems with the hardware will show up. It was easier because the actual tuning (once you’ve got the glitches worked out) went smoother than I expected. I ran into 2 minor glitches that ended up taking a lot of time to figure out. The 1st was that my aftermarket performance ignition coil was drawing the voltage down too low at the coil. It still produced a spark, but the computer had problems detecting RPM properly. This was fixed by removing the ballast resistor (not needed anymore anyway). The 2nd was that I used improper tubing for my vacuum line. This tubing worked fine while cold, but once warm it got soft and “sucked together” like a straw in a thick milkshake. Switching to proper automotive grade vacuum line fixed this.