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Hello all, long time reader first time poster.

I'm not 100% sure if this is the right place so please excuse me if it is not. So I have had my 1995 skyline r33 gtst for about 2 and a bit years and have started to notice an issue that has gotten worst about 4 months ago. This car is not really my daily as I only drive it once or twice a week if I'm lucky as I get lifts to work and use my girlfriends car if needed.

The issue is, when I'm driving and give my car a bit around 3-4k rpm seems like there is a big lack of power/boost and then picks up from there after 4k - 4.5k then I hear a bit of a popping noise coming from my exhaust and sometime maybe smoke (in first gear it seems fine), when it first started it was just the popping noise and what I thought to be a blocked fuel filter or something. So I bought a new one and replaced it and notice that when I turned my car on all the hoses had a crack in them so I turned her off and bought new ones and replaced them all. Now I thought I had found what the problem was so I went for a test run and it seems a bit better but the problem was still there, I left it for a while to try and figure out what it was. I thought maybe it was the pod filter needing a clean our or something so I bought a new one rather than try and clean my Apexi one as I was not 100% sure on how to clean it. But still no luck problem still there and seems that its getting worst every day. I have done some reading and have pin pointed to a couple of things that it might be. One the o2 sensor or two the AFM. Just wanting to know a bit about this before if try and so anything am I heading in the right direction? Has anyone had this happen before if so what was your issue?

I'm a bit over due for an oil change(1.500km noticed a drop in oil pressure on the dash but not much) so I was going to do that this weekend or on Monday and see if this helps any. But if anyone could point me in the right direction to what this could be that would be great.

Here are my spec and hope this helps as it could be something different.

Blitz intercooler

Apexi pod and cool enclosure

3.5inch xforce exhaust turbo back

HKS EVC boost controller (running low on 8psi issue not so noticeable on this level) (high on 12psi really noticeable, never had an issue running on high until I noticed this issue a few months back)

R32 fuel pump the guy who had this before me changed it over. Said it was a bigger pump then the r33 (not sure if it's true?) might have even said 34 not sure it was two years back but I can check when I get home or might have been a different pump altogether.. not sure.

She's tuned to run on 12psi and I run on 8 for when I'm just cruising around she hit 204.4rwkw

Any help would be great thanks.

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Im not expert but from what Ive read, the o2 sensor affects the car at idle and low revs - not at the rev range you're experiencing trouble.

If there's popping and smoke (I'm assuming black smoke) then its implying unburnt fuel.

And if the problem only exists within a certain range then it's probably not the spark plugs or coil packs.

So something is causing a timing problem then?

Could be afm? Fuel pump maybe.

ok not a problem, i not long ago had my timimg done like maybe 4000k's, but i didnt think it would be this otherwise it would be happening on low boost and would have happend soon yeah? i'll try gap and reset and see what happens, i might even just replace the spark plugs if they are dirty and might also clean the AFM while im at it i looked at it last night and my engine bay is a fair bit dirty. my old nissan exa had an issue like this and it turned out to be the coilpacks so i'll check for cracks and the contacts and see how they look. if nothing then i guess it could be the fuel pump or filter or something. i'll have a look around for leaks ect and see what i can find.

i'll keep you posted, i wont get around to it till maybe monday so might be a couple of days.

thanks for the advice.

So i decided to make time and do it today. took a look at the AFM and gave her a clean with this AFM cleaner i found at super cheap. put it all back together let her sit and idel for a bit and when for a spin, all seemed good a tad smoother on low boost so i thought i'll give her a go on high boost and still the issue was there.

tooker her home up with the bonet and took at look at the coil packs, started from the front and worked my way down one at a time looking for cracks or any sign for what could be the issue, took the 4th one off and all looked ok and i looked in side and seen this while cork like dust inside. think to my self has to be the spark plugs on the way out. checked the 5th same thing checked the 6th all fine so i think its these two that are the issue. am i right in thinking this?

didnt get time to go down the store and get new plugs so i'll have to look into it tomorrow.

Does any one know the part number for the spark plugs if so could you be so kind as to post them and any type?

cheers for the help lets hope this is the issue.

ok oil change useing motul syth oil and new spark plugs, still happening... im thinking it could be injector or something.. any idears? Also once i was done the HICAS light came on i know this is to do with the rear wheels, i had to take off alot of stuff to get the the spark plugs but im pretty sure its all good. Also i notices a littel bit of water coming from the passanger side sorta around where the turbo is, what could this be from?air con or waterpump? im not that grate with cars but I do give it a go so anyhelp would be great.. i think im going to have to take her to get looked at. i live in the country region gippsland so I'm limited as far as performace places go :(

So turns out it was just the reducers on the intake they had cracked right through on the bottom, replaced with new ones and is pulling harder then ever and no power lose or smoke.

Only problem left to fix now is when im running on high boost once i hit like 5.5-6k revs in any gear it starts popping like crazy like its starving on fuel then just before 7k it hits a flat spot.

any ideas?

Edited by Jarmanski

Do you know your afr readings? Could be dead fuel pump I would never put a second hand pump in waste of time really especially putting a pump in that's older then your car.

Nah dont know I'm going to look into getting a cable and ecu reading software. just not sure what one yet and how much i want to speed on the cable. what should it be at?

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