GT-X cutting randomly

[Vipe]

Hi everybody!

I have 323F/astina with gt-x engine.
I searched forums with same problem and tried almost everything.

It has 2.5" exhaust with catalytic converter, pod filter, large fmic.

My problem is that engine cuts @ 4000-6000rpm randomly at first or second gear. Cut comes only one time and sounds like no spark. On bigger gears I have no problem. I think boost goes down a little bit and narrowband AF meter shows no lights, when cut happens. I have done many things and it is better now, previously cuts were very common in bigger gears. Now only 1st or 2nd gear, usually first gear and not always.

Boost is about 0.7-0.8bar max, I have bleed valve and if I raise boost, cuts may come more often. Still I don't think it is a
fuel cut. I tried to connect from ecu 2S pin (overboost warning) to a light, but there was no activity when cut occurs.
First cut occured without bleed valve, so I think that it is not a problem. Same setup have been on my car 3 years, and suddenly this summer cutting have begun. I haven't changed almost anything in ½ year.

I have fixed these things:

- New rotor and distributor cap
- Other distributor
- New ignition wires / coil to dizzy cap wire
- Other coil and ignition module (both coils tested)
- New spark plugs (ngk bkr6e-11 and denso iridium IK20, now bkr7e-11 because other plugs were little too white/chalky)
With denso iridium plugs, problem came more often, tried also lower spark plug cap on ngk plugs to 0.8mm.

- Cleaned fuel pump and fuel filter changed ½ year ago
- Override fuel pump resistor pack, now 12v all time to GT pump
- Cleaned and stiffened hall sensor and coil connectors, both were a little slack
- No fault codes
- Tested piping from turbo to throttle body, welded some leaks.
- Tightened dump valve
- Made new grounding wires from battery and from engine to body

I hope someone can tell me what to do next?


PS. Here is pics of my car in our club website: http://www.323fclub.com/?sivu=profiili.php&nick=Vipe

[DavoAust]

after it cuts does it then continue to rev past where it cut out?
if not that definately sounds like a fuel cut

[Vipe]

When cut happens at 1st gear usually about 5000rpm, revs drop a little bit, but with full throttle pressed all time it revs normally to the limiter, if wanted to do so. With second or bigger gear, no problems on full rev range.

In first gear revs raise very fast, so is it possible that air or fuel is not supplied enough fast for rev raising or something?

Maybe I take my afm off and open it and check that everything moves smoothly. I tried flap and it opens ok, but that was quick check.

If it would be fuel problem, I think that would do different thing than just cut.
And it would occur on bigger gears also.

Weak spark can also to be the problem but again it would do it on other gears.

Sometimes cut happens when I pull hand brake up and burn rubber. I thought that it was some loose wire connection because of shaking (no lsd). Then I found that coil power wire was little loose, and I could shut engine down by moving it, but that is fixed now like hall sensor connection on distributor.