RB25 Runs very poorly

[Raipe]

So my RB25 has compression, gets fuel, gets good spark, has injection pulse and timing should be ok but it wont run (idle/response throttle at all). 1 of 50 Cranks it runs, but very poorly. While it runs i have unplugged the MAF and it stalls right away. By turning the CAS, rpm will change maybe by 100-300rpm  but it doesnt effect pretty much. Turning also the TPS does not effect so much that it would help, maybe with 100-300rpm also. While pressing the throttle it sound really wierd, i took an video of it: 

 It backfires alos alot if it would not start. Any suggestions what should i check? Here also a video of it while cranking it: 

 

[Duncan]

sounds like the distributor leads are out of order....so I'd suspect failed CAS first.

But, has it ever run in the current setup? has something changed lately? what ECU is it, and can you check RPM through the ECU?

[WR33KD]

Did you install the motor? If so how do you link the looms together?

[Raipe]

I forgot to mention that the car has been running well before. The CAS should be ok, i tried it on another skyline and it worked well. It has an brand new ecu on it because the last one fryed somehow. it didint make the injectors pulse while spinning CAS. It is running nistune and wiring specialties harness

[JustJay]

Well as embarrassing as this is to admit, my R33 ran identical to that after swapping in ECU with Nistune.

Had nothing to do with the ECU itself but the plug/connector. I had not tightened the bolt down far enough on the connector on the ECU. Once I tightened it ran perfect.

Needed a set of plugs as it fouled them bad.

[Raipe]

Problem solved pretty far. Ecu got only 6-8v. By changing the alternator it helped a little bit but somehow the voltage was still too low in the ecu (10.9v). Everything else like maf, injectors, coils etc got perfect voltage. I took one wire off from the starter and it immediately rised to +12.8v in the ecu, pretty wierd. Maybe an ground leak/voltage leak or something else like an bad starter..