Just like the others one problem after the other my 1990 honda civic dx stopped on me changed fuel filter nothing heard pump kick off and on change pump nothing, check code 16 flashes the injectors change just the main one still would not start change main relay still will not start change switch still nothing change ecu unit still light on ecu don't even come on anymore no power at relay plug or fuel pump.when I hot wire the fuel pump she runs fine don't know which is the hot wire for the relay plug I have a 4 pong relay help help

Many relays have a diagram on them, Many have a Constant hot to the coil of the relay, and am thinking the ground is from the ECM, not the Ignition Switch.
TXGreasemonkey has Very Good On trouble shooting Hondas to Verify. Then you have the contacts, 1 is to the pump and the other is from another fuse.
You need to see if you are getting voltage to the coil of the Relay or are you lacking power on the contacts that connects to the pump?

chicoman; I have fire to the coil, what is a ecm,the alt solenoid fuse can't find the wire that goes to main relay its not like a normal fuse box where you can look behind it and follow the wire.

The ECM stand for Electronic Control Module(The Brain).
I would check here, Very good info:
https://www.askmehelpdesk.com/cars-t...les-46563.html

I changed the brain twice I call it the ecu, but the relay plug in has no fire on either pong 1,2,3,or for the lite on ecu don't even come on are give a code anymore.

I will see if I can find a schematic for your Fuel, CaptainRich is good on schematics and may have a post on this.
I wouldn't change or replace anything until you have the fuel pump schematic, if you have No hots, it is likely a fuse.
The Service Manual should be your first purchase.
Did you look through the link on my above post? Just click on the Blue words, then check out Main Relay, And Relay locations and testing, answers are all there.
Good Luck

I have a 1990 Honda civic ex model 1.6L the car runs great in the morning,but in the evening the car will not start.

billyboy49, sounds like the main relay needs replacing. The cold solder joints on the PCB are expanding and losing continuity, during the heat of the day.

I believe they had a recall on the Ignition switch, It is a real problem:

Honda Accord Ignition Switch Replacement - YouTube

Shows how to test and replace.