R33 Gtst S1 Issues (negative Timing, Misfiring)

[Paymh]

Hey all, my consult cable finally arrived today and I've been playing around with it. I noticed that the timing sits at 15 according to the ecu but if you rev it in neutral then let off it drops to between -3 to 5 depending on what it's revved to then goes back to 15. As this is my first skyline I'm not sure if this is normal, from searching it seems like it isn't? Could this be caused by an atmo blow off valve (replacing soon) as the timing drops at the same time as it dumps or by bad timing? The car won't rev above 2,500rpm without serious misfiring under load so is this another sign of bad timing. My first thought for the misfire issue was bad coils as two seem to be from a rb20 and the other 4 are OEM, meaning two already died from previous owner, but now with the timing doing what it is, I'm not sure. I haven't had a chance to get it checked out because its unregistered right now so taking it to a tuner is tough.

TLDR;

• Negative timing after letting off gas
• Won't rev above 2,500rpm under load without tonnes of misfiring, revs fine in neutral
• Any decent mobile mechanics in brisbane area

Thanks!

[GH05T]

sounds like a bad air flow meter, re solder it (there is a how to here somewhere)

*edit*
have a read, might be your issue.

http://www.sau.com.au/forums/topic/113284-fixing-your-rb26-afms/page-3?hl=fixing+afm#entry7380863

Edited March 15, 2016 by GH05T

[Paymh]

sounds like a bad air flow meter, re solder it (there is a how to here somewhere)

*edit*

have a read, might be your issue.

http://www.sau.com.au/forums/topic/113284-fixing-your-rb26-afms/page-3?hl=fixing+afm#entry7380863

Thanks mate I'll give it a go and report back

[Paymh]

Alright so re-soldered the AFM, now revs up to 5000rpm instead of 2,500rpm. Still get a lot of misfiring at the 5k mark now as well as intermittent misfiring from the 3k rev range. So it seems the AFM fix did somewhat solve it. Would the 5k misfires be a coilpack issue?

EDIT: I feel pretty dumb now, popped the bonnet and found the vacuum hose for the fuel pressure regulator had popped off during the test. One would assume my issue was solved by re-soldering the AFM and the 5k misfiring was caused by that.

Edited March 15, 2016 by Paymh