1978 n/a ma70 stalling + no diagnostic codes light

[wuder]

So the story started when I decided to rebuld my 7mge after previous owner and make engine bay cleaner. Took off all cooling hoses, throttle, intake and exhaust manifolds, then took off head, cleaned it, replaced valve stem seals, put new gasket, then built everything back.

Important to notice, EGR is bypassed (including vacuum lines change) as far as I can see.

Connected all the plugs, connected ECU, put timing belt(using manual, following all steps), set distributor (again following manual, so the timing should be fine). Basically put everything(except cooling) the way it was before I took it apart.

Buuut, when I try to start it cranks, revvs once and stalls immediately. What I checked:

1. There is a spark on plugs
2. Fuel pump works, fuel comes to the rail and squirts fine(unsure about injectors though)
3. Starter works alright
4. Rechecked timing belt many times, everything is fine(except that I don't know how to check if I'm 180 off, but tried both possible ways, no change)
5. Checked ignition timing(distributor). Even took the cover off and put it to first cylinder manually
6. Rechecked all the vacuum lines, they're fine
7. Rechecked the grounds, one is on the head near the exhaust, 3 near the fuse box close to battery, one on alternator, 3 under intake manifold, 1 behind the dash, 1 to the right from drivers side(close to gear box) and one on the left side door sill(inside)

Still no success, is holds a little using accelerator(opening the throttle) manually, but does very weird screech noise.

Another thing I noticed is that I can't read diagnostic codes anymore(it was possible before rebuild). I jumpered T and E1 in diagnostic box and nothing. No check engine light at all, it's just off. Only alarm and "doors open" lights are on. I disconnected the dash and checked if the problem is in the bulb... Nope, there is just no signal to it at all(used multimeter). Rechecked all grounds again, nothing much, didn't find anything missing or displaced.

Honestly it starts to piss me off... Spent a week on it already, no success at all... By the way, today tried to put a little gas directly inside the intake manifold, sound was a little louder but nothing changed.

Would really appreciate the help guys as I have absolutely no clue anymore... If needed I can attach any photos and put videos.