2016 Elantra GT Crank NO start
 

I just changed the engine and transmission
I used engine harness from the NEW engine
My car 2016
New engine 2017
Car will run on start fluid
checked fuses
I'm using a test light.
No power to pink wire on fuel pump while cranking. Battery was disconnected for over 30 days
IM DESPERATE...I ran out of money
Please help this 60yo !!!!!

I am 60 years old. 61 in the next few months to come.
You have a crank no start. However it starts with starter fluid.
Which means it is a fuel system issue.
In the engine bay fuse box, there is usually a c/fp (check/fuel pump) test point.
Should show 12 volts while engine is cranking.

If you don't have that 12 volts then go to the fuse box and check the pins for the fuel pump relay.
The socket should show two point with 12 volts since Hyundai likes to use ground side switching.
Looking at the relay, try to determine which ones are pin 30 and 87.
Pins 30 and 87 should be the load side of the relay ... going to fuel pump.

If you put a jumper between pins 30 and 87 in the relay socket then it should turn on the fuel pump.
You can listen for fuel pump to run and/or try starting engine.
If it runs then the issue is on the control side of relay.
If it does not run then issue is on the load side of relay.

The other thing is did you swap over the 2017 ECU????
Do not know if the old ECU will have the same pin out for the new engine

Note: The control side of relay is the ECU.
So, Danger, do not short the control side for ECU.
It can damage the ecu.

If the info to tell you the terminal nos is not on the top of the relay , it is usually shown on the underside of the relay.