91 Gtr Jolts @ 4000 Rpm

[boegtr]

i just got a 91 GTR. it runs smoothly until it hits 4000rpm @ full throttle. i cant get past 4000 rpm cause it jolts heavily. i revved it to 6000rpm and it seemed fine. im thinking its my sparkplugs but im not sure cause u can rev it past 4000 without problems. sorry for being a n00bcake but pls give me some ideas and solutions. i heard rumors that old rb26 engines has an oiling problem @ high rpms. is it caused by this oiling problem?

Edited March 3, 2008 by boegtr

[G-Money]

check ya AFM's

[marks33]

i heard coilpacks can break down in a rpm range .Might be worth swaping tem with ya mates ones.

[Amec]

could also be a boost leak.

[N1GTR]

Is it when the engine is cold?

You might have an aftermarket ECU with cold start enabled (wont rev past a set limit until its warmed up)

[boegtr]

thanks. ill check them tom and ill keep u guys posted. cheers!