RB26 shuddering, ignition problem? HELP!

[mancolog]

Hi guys I am about to loose my mind about the ignition problem of an RB26 engine. I saw others having similar problems but they solving methode did not work on mine so far.

Problem:
The car was running fine the first month I built it. Suddenly after a rolling night it started to random shuddering for some reason. The next day it ran fine and a while after it started to misfire and the engine strated to ran on 5 cylinders again. The misfiring is in consistent the problem will come and go, some times it last few minutes some times it wont even go away till the next day. This problem started to get more frequent with the time. I don’t know what is the reason but after 5-15 minutes of driving time the car starts shudder al a sudden. I can’t tell which cylinder misfires, because it changes all the time. I renewed the harness and put a new İgnitor. The problem got solved for 2 weeks and it started the same problem again. I read in forums that RB26 ignitors are pretty problematic and they fail real quick, so I switched to Z32 ignitor by re-pinning. The problem got solved only for 1 hour. And again I loose power and the car keeps running only on 5 cylinders. The shuddring occurs both in idling and boost .
I can not solve this problem since 7 months. Any İdea ? Did anyone got this problem and solved it?
Fixes:
I did a compression test. Results were great
I switched (3) RB26 ignitor and (1) Z32 ignitor (thinking that I am supper unlucky to get malfunctioning ignitors)
İnjectors were flow tested
I changed 3 sets of sparkplugs
I tried another set of used stock coils (I think if a coil goes bad, it just wont work again)
I changed the top and coilpack harness with a brand new ones

The setup is:
AEM-EMS v2 with Aem AIT and AEM map sensor , AEM uego and AEM (cas disc converted)
OEM maf and o2 sensors are removed
Stock injector (flow tested) ,Stock coils, brand new top harness, brand new coil pack harness, z32 ignitor (re pinned)


I am trying to generate solutions. Next step I will try another ECU but I keep wasting time and money trying to find the problem...

[gawdzilla]

that's pretty weird. are you sure the miss is on different cylinders each time? if you've change the ignitors and the coilpacks, AND cleaned/flowed your injectors i would say it is either your CAS or the AEM itself. i don't know too much about the CAS disc conversion and how reliable it is, but I'm assuming this is to fix the skipping with the earlier AEMs and oem CAS?

if i were you, i'd see if i could rent a known good AEM converted CAS from someone for a borrowing fee / deposit to test out.

another thing you could try is to go back to an OEM CAS and run a PFC or something just to see if you can reproduce the problem. that way you'll be sure it's not your ignitors/coilpacks/injectors/wiring at least.

but yea either way it sounds like you'll need to rent a few expensive parts to test on your setup.