Geo_gan

Fixed. It was the Subaru immobilizer in the end FFS...

Well i have starter out (totally stuck to surface - had to be screwdriver + hammered out, then fell to ground below and cracked rear cast case!) and no damage can be seen on starter or main crank that I can see in hole... I suppose I could try and rotate it around the entire way while recording... New starter on its way...

Yes it has aftermarket Clifford alarm... I know I was thinking is the Clifford stopping spark for some reason, but I don't think so becasue I enter the code in keypad as normal which disables the imobilisor and powers up the ignition as normal (before code entry there is no power) Yes I found some service manuals in the only STi maunual that matched the ECU plugs/pins to mine and checked continuity from cam, crank, coilpacks back to ECU and all seem to be OK. Also did MAF and MAP sensors too. Also have oscilloscope on crank and front right cam sensor and waveforms look correct. But for some reason ECU is not sending out the spark signal during crank so anyone know what could cause it to do this?

I did actually give it a few whacks with a heavy rubber pallet, but this did nothing, then I tried hammering a screwdriver into the slight gap between them, and it just sank down about a mm and then got stuck. Gave it heavy blows too. Can't believe it could be just "stuck surfaces" since the screwdriver has separated the top about 0.5mm already. I stopped after that on the day. Watching some youtube videos, the thing is supposed to just fall off once two bolts are out. The top long bolt gave me awful trouble too, and when it came out the top 5mm of its thread was completely destroyed. So I don't know what happened with it, may have been like that since it was put in years ago... hope there is enough thread left to actually hold the engine when it goes back in (this appears to be a main transmission/engine holding bolt isn't it? Where did you get a replacement anyway? OEM or cheap copy? I won't know until I have a look what kind of state it is in. Looks like original Denso.

My car war running fine until one day it just decided "i am not going to start at all". It cranks but no ignition, no spark. I had driven 30 miles to event and it would not start for return home. I have tested and am more or less happy with following: Cam sensor (single one on front right hand side). Tested resistance and also during crank using osciloscope and see the normal cam signal waveform. Is there another around back of engine for other side of cam? According to service manual there isn't. Crank sensor (single on top of crank). Tested resistance and also during crank using osciloscope and see the normal crank signal waveform appearing. Coilpacks. Not sure - but I know they were working fine up until this immediate failure happened. No way 4 seperate coilpacks could go at the exact same time. And there was no single one gone either as engine was running normally. Tested voltages to coils and continuity from coilpacks back to ECU. All fine. Tested spark plugs in coils, but can see no spark. No way all four NGK Iridium spark plugs could go at once - they worked fine on same day it failed.. literally 20 minutes before. There are NO pending codes in ECU (4 historical ones but I don't think they are relevant right now if it doesn't see them as pending) Checked battery with battery tester and it is at 98% health and 99% charged. Can't do battery crank test as engine won't start obviously. Checked engine grounds and they are OK. Can hear the normal Walbro fuel pump noise when ignition is turned and it primes up. Can also smell petrol from cylinders when I crank with fuel relay still connected. I am able to hand turn the engine with one hand and wrench on crank pulley so engine is not seized. The timing belt looks OK... no damage visible... i haven't taken off centre cover or crank pulley so I haven't checked full alignment, but this has run fine for years without problem. May need a normal timing belt change. For the first 30+ times I cranked trying to diagnose this, I was getting normal sounding crank, but now I think starter has died... it started making that screeching noise like engine is running when you crank (like the starter cog not engaging with spinning flywheel), and then after will only very slowly crank, not normal sound. So I think I killed the starter and need replacement. Also when I tried to remove old starter and took out two bolts holding it, it did not fall out - it is stuck solid to the crank case... will not move... can't get it off... what could cause this?? It can't be "jammed" on flywheel... because I can turn engine easilty by hand. So on idea whats holding it on now. Is there some other parts of an 2.0 STi engine that would cause the ECU to decide not to send the "spark" signal to coilpacks during crank? AVCS? Other block sensors I don't know about that might have failed? MAF airflow sensor? I forgot to try cleaning it but I do regularly clean it. Could a bad boost control solenoid stop ECU from sending spark signal? It's annoying me that ECU just decides to not send spark signal to coilpacks but won't tell me why not!! I don't want to go throwing money at replacing all sorts of random sensors... and obviously I can send to garage but now that would require a tow-truck from my house so not cheap! Any ideas?