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I cleaned the AAC and AYC, replaced coil packs, fuel pump, fuel filter, all the lines.

My thoughts were that it was fuel related (hence a stab of the throttle to pick the fuel pressure up) but it could just as well be not enough air, so no, i'm out of ideas too man :D.

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Yeah that's what I thought initially too. But I dropped my fuel line off whilst it was cold and there is still furl there so it's not draining to tank. An performance isn't hampered so no starvation. I replaced my ayc, cleaned the aac, changed to a oem bov, cleaned the afm, adjusted the idle, calibrated the tps, checked the coolant sensor, checked for boost leaks, replaced the fuel filter and lines.

It's got me stuffed. I'm just going to start replacing things now. First up is aac and coolant probe.

have the cold start idle issue too. Car pretty much stalls as soon as it fires up if i dont blip the throttle...

When i had aftermarket injectors, z32 afm (with plug) and tune car would fire and not struggle...

So its either the injectors, afm or tune in my opinion...

I've had my rb20 stock injectors cleaned before fitting in and still have cold start issues. So that could mean afm or tune...

  • 2 weeks later...
  • 6 months later...

Any ideas yet? Replaced my injector o-rings as one was leaking, Removed and resealed all joiners on the intake. Cleaned the aac again. Adjusted the throttle. Still have the issue. Funny thing is from time to time it starts beautiful cold.

Nissan Fast AAC valve.

I have pulled apart the iacv-aac valve (23781M in picture) and cleaned that.

However ive never heard of the air regulator? (22660M)

Perhaps the problem lies with the air regulator? Have you cleaned/replaced that before?

post-10032-0-24297800-1337079728_thumb.jpg

What they do is in the name. AAC Auxilary Air Controller and IAC Idle Air Controller. And i have replaced the IAC and cleaned the AAC. But i don't believe its either as once started it idles perfectly and does not faulter when load is placed on and off the engine (A/C). Im thinking electrical as i have noticed the first few cylinders firing sound almost like its mis-firing. Then once it gets up to speed ( >300rpm) it settles itself down. Ive also noticed when its cold there is a surge as soon as boost is coming on. Hence why im thinking either coil packs or maybe o2 sensor.

No not yet, but i have replaced it with a walbro 260lh/hr pump. But i don't believe the issue to be fuel, as i can prime the system a few times and make sure the system has full pressure then start it with the same issue.

Thought i would keep this going as a record.

So far i have

Replaced the IAC

Cleaned the AAC

Checked for boost leaks and replaced a few hose clamps

Resealed the injectors

Replaced the fuel filter

Replaced the fuel lines

Replaced the fuel pump

Replaced the vacuum hose

Adjusted the tps to 0.4 at idle and 3.97 at WOT

Thought about setting it on fire

Bought some petrol

Removed the turbo timer

Removed the immobilizer

Replaced the o2 sensor with a new ford el type

Replaced the spark plugs with BCPR6E -11 gapped to 0.8mm

And still nothing. I played with the tps again yesterday and moved it a heap out of wack. I found that it would start beautifully but between 2-3k rpm it would splutter and stall. So i would assume that the idle was switching around there. With that i would say it is a TPS issue?

Edited by beemae30

In Townsville. And no i haven't tried another ecu yet. Thats the strange thing even with the throttle held open it still struggles to fire for the first few revolutions, then once it fires a few cylinders it picks up. Otherwise with the throttle at idle it takes about 5-10 revolutions of missing before it picks up to normal idle otherwise it stalls then will fire and run to idle straight away on next turn of the key.

Ok so took it for a drive today for an hr or so. Hesitation between 2-3k is gone since i readjusted the tps back to how it was (0.4v at idle, 3.97v at WOT) But now the idle is fluctuating and i can't adjust the aac. So i think ill just buy a new TPS and AAC and see what happens

Try crimping the fuel return line after the fuel pressure reg when starting to raise te fuel pressure. the reg may be getting soft.

With the tps if its not set correctly it may not be in the idle maps. Try lowering it to .35 or so

Well I don't have anything with me ATM to check the tps again as I'm in Mackay for inductions. But it's definitely set to 0.4v to 4v. I've also noticed another sympto that's only just started, when i drive it cold , she sometimes misses until the first sign of boost or i give it more then 20% or so throttle then it's ok but it doesn't like driving at partial throttle occasionally. I've only noticed this since I replaced the o2 sensor but at the same time i played with the tps so im hoping fpr, maybe injectors running less pulse width cause of altered fuel maps = more fuel fighting fpr? Which bring the issue on just before boost? I dunno clutching at straws here. But it drove for 400km last night no worries

Edited by beemae30

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