Engine not starting

Hello,
I replaced the cylinder head on my Jimmy from 2004, G13BB engine.
Now the engine does not start. After several testes it came out that injectors 2 and 3 are not working even if injectors are tested and ok.
Any help is greatly appreciated 
Thank you 

How do you know injectors 2 & 3 are not working? Is there no fuel to these cylinders?

Or do you have a misfire on these two cylinders?

I assume that cylinders 1 & 4 both fire, but that isn’t enough to get the engine running?

Assuming you have checked ignition and fuel pressure can you check the injector wiring to see if you have an injector pulse? If not it might be wiring, either trapped or a connector.

Engine is trying to start briefly. It I put brake cleaner on intake, is running few seconds.
I removed the injector rail and had someone crank the engine — I noticed that injectors 2 and 3 weren't spraying fuel.I swapped the connector from injector 1 to injectors 2 and 3, and they both sprayed correctly.I measured with a multimeter — all four connectors have +12V.Then I used a test LED on each connector: injectors 1 and 4 show normal pulsing, but 2 and 3 flash once or twice, then nothing

If you have fuel & spark (at the correct time) on cylinders 1 & 4 the engine should start & run, albeit not very well, but, it should run.

Have you checked for spark on all four cylinders? In a no fuel situation (no fuel at all), the engine should start & run on starting fluid for as long as you keep spraying the starting fluid.

If you can't do either of the two above you need to figure out why and cam timing would be the first place I would look, because that would have been disturbed when the head was removed.

You say the head was replaced - new head? "good" used head? or completely unknown head?

Is a refurbished cylinder head, complete, pressure tested. The camshaft is mine from old cylinder head. 
Both crankshaft and cameashaft are aligned at marks.
Even if timing is bad and ignition is not working, injectors 2 and 3 should work, even if engine won't start.

I would suspect a wiring fault or bad connection to the injectors. If you swap the injectors (or wiring) over does the problem move or stay with cylinders 2 & 3?

The other thing i can think of is the crank position sensor, is it ok?