My friend has a 98 Eclipse RS with a Star stage 1 kit, our FMIC kit, SAFC, Vortec FMU with 8:1 disk, and 315cc injectors. he is having a little hiccup that has me a little confused. if you mash the gas hard in first, second, or 3rd gear, you hear boost building and the car starts making power, but its like it is bogging down or something for a second or two, and the AF gauge is lean for that second ot two, then the AF gauge smacks up to .96 and the car ROCKETS forward and is completely fine until redline. if you just slowly roll onto the throttle, and let boost and fuel pressure build gradually, it doesnt do it, least it hasnt with me driving it. any ideas? the MAP sensor voltage is fine, he has a missing link. only thing i can think of is maybe a small kink in a fuel line somewhere, FMU clogged a little, or could it be the throttle position sensor? any ideas guys? thanks for any help.

Make sure you are using the 2.72 inch disk in the S-FMU. I had the same problem with the large disk on the same setup. Once I put the 2.72 inch disk in it cleared up a little. I think the fuel system is dumping too much fuel and the ecu is trying to even it out. The ecu leans is out but way to much for the amount of air being forced in. Then it sees it is too lean and richens it up again. The 2.72 inch disk will clear it up a littl but you will still get a hesitation. Just not as bad. Put your idle fuel pressure at 30psi as well. Run the vacume source right off of the turbo, not the intake manifold. This way the S-FMU sees less vacume.

he has the regular FMU with a 8:1 disk.

that rate of fuel pressure is too high. He needs a S-FMU or smaller injectors.