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Stuttering Up Till 4500Rpm

Borci88

By Borci88,
in Engines & Forced Induction

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Borci88 Veteran

Borci88

Posted
Posted

Hey guys,

Have a little problem with the latest Skyline I bought. Through any gear from 2500rpm till around 4500rpm it will stutter and make boost but bounce around 10psi up and down as if the power is switching itself on and off. I assumed it was the stock boost solenoid but that is looped and not connected to the wastegate (although still wired in through the plug). It does have a boost tee hooked up and runs 10psi after 4500rpm. Mods are full exhaust system and GReddy front mount but other than that nothing engine wise, I can't put my finger on why it's shuddering until the "supposed" boost solenoid would allow full boost.

Cheers!

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defari Grand Master

defari

Posted
Posted

plugs should be gapped to .8mm

whilst you have the plugs out, check the coilpacks for cracks - you can tape them up / silicone them however from numerous posts this is only a temporary fix, new splitfires ($500-$600) are well worth the investment. Havent used or researched yellow jackets (cheaper) however if your not going for bullshit huge horsepower then they may be an option if your wallet is light.. oem nissan packs are just as expensive as the splitfires so may as well go with the splitfires..

Id first rule out anything else before forking out for new coilpacks.. it could be a simple fix..

get the vac leak fixed, whether or not its the problem its still a good idea to fix it.. as they say "a stitch in time saves nine"

Rolls Grand Master

Rolls

Posted
Posted (edited)

I know there's a tiny leak in the vacuum hose that runs from the manifold to the rocker cover and that does effect idle from time to time, could that also effect coming onto boost?

a tiny leak on vac becomes a massive leak on boost, fix it., almost certainly your issue.

if you are running extra boost from a big exhaust/controller this could be causing havoc with the tune, remove any boost controllers and see if it fixes it, if it does then time for a remap via a nistune etc.

Read the misfire at 4500-5000rpm thread for other suggestions, there are billions of similar problems in that thread.

Edited by Rolls
Borci88 Veteran

Borci88

Posted
  • Author
Posted

Cleaned out the AFM and changed the pod to something a bit newer and it has made it run a lot better but it does still stutter a little bit coming onto boost, will have a proper look at that vac leak tomorrow and hope that that fixes the problem.

Cheers!

Borci88 Veteran

Borci88

Posted
  • Author
Posted

Mmm sealed up the VAC leak and it still does it, I'll have to take a video to demonstrate what it's doing. Especially in first it climbs revs but doesn't really go anywhere, might have to watch the boost gauge next time but it just accelerates like an NA.

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