We just installed a homemade kit on a d16y7 dx motor and at narrow throttle sometimes it will hesitate real bad, also in the morning the idle will fluctuate and go up and down and when it goes down almost dies out, like it's choking.

Here is the setup:

5 fish tank check valves between a crx map sensor and the intake manifold
10:1 FMU
B&M FPR
T25 turbo, HF manny
Stock fuel pump
Timing retarded 2 degrees
DSM smic
2.5" dp

 

check for leaks in the checkvalves. make sure you dont have one in backwards. if there is a leak between the intake manifold and the map sensor it might cause that.

 

when I install the check valves, do they have to be inbetween the map sensor and the "throttle body" or can it be between the map sensor and the "intake manifold"??