I have an 89' CRX - DX. I am gonna drop in a ZC. That's what I am saving up for right now. I have come across a Greddy turbo/ intercooler kit that I can't pass by. Now if I drop in the motor and then install the turbo, will I have to upgrade the fuel pump, fuel rails, injectors, & fuel pressure regulator.

There are a couple of ways to manage the fuel on a turboed motor.

You can use the boost dependent regulator and high pressure inline fuel pump. For example, the Drag kit comes with a 12:1 regulator(i believe) and a high pressure inline fuel pump. Another route is to use larger injectors, an intank fuel pump, and use a fuel computer ala S-AFC to tune the fuel delivery. The last option is a standalone unit. Here are some examples:

ZDYNE Gold Ecu
Hondata(not applicable in your situation)-They only 88-91 B16A1 ecus
Haltech
DFI

There are others that I can't remember but that should get you started.

Is it a complete Greddy kit? If so, it should come with a fuel system too. The best and cheapest way to get the extra fuel on a low boost turbo system is with a boost dependant fuel pressure regulator(the vortech 12:1 fpr is the best) and a high flow in line fuel pump(you can find a NOS inline pump for cheap). The stock fuel pump in your car isn't too small to handle the swap and can support slightly more than 200 natural aspirated hp before it needs to be replaced with a higher flowing one.

GREDDY turbo, TRUST intercooler, HKS BOV, 9psi boost w/stock wastegate....

greddy makes a turbo is it a modded 92-95 civic one?

Nevermind, I found another kit. It's a much better one. Costs a bit more, but I will get a lot more.

by whom?

It is by Greddy, slightly modded