R34 Gtt Reving On Its Own When Warm.

[Artic Choc]

Ok so i got my car back from tune a while ago and the car ran perfect except for bad ignition. So last week i replaced the coilpacks with brandnew splitfires and fixed the problem but after ringing 2nd gear to redline to see if it had truly been fixed which it had a new problem arose.

When i turn th car on from cold itl rev up to 1.4krpm then rise to 2k where it will sit, until just under optimal running temp where it will drop too just over 1k.. once it hits running temp the car will endlessly bounce between 1.2k and 2krmp.. sometimes itl hold 2krpm for a couple seconds but continue to bounce.. it also "Rev matches" when traveling through neutral to change gear in anyway.. its very hisitant with throttle too in the low rpm range of 1-2-3 i feels like it just cuts out when letting off the pedal but jerks back on when back on throttle theres no smooth way round it..

Now things ive tried:

Smoked out the vacuume lines to try for leaks.

Cleaned and resealed IAC valve(new gasket and goo

New coils and sparks.

New fuel fillter and flushed fuel tank and tried new fuel/mix

Cleaned Afm which apears to be in good working order.

Checked ecutalk for error codes and reads code 55 no errors

O2 sensor is reading within the voltage of being in working order..

TPS is reading correct voltage.

Im litterally stumped for any other problems. Mod list is in sig for refrence

Any info or help would be a godsend as its making me pull my hair out as its bloody anoying and id not like to ruin the engine..

Ive searched everywhere and the answers ive got ive tried to see if itl fix the problem.

Last option is i take it back to the tuner and see if they have any ideas

Thanks

Ps. i can get a vid if youd like il just have to put the car back together first..

[Nismo34R]

If you've done all of the above.. My guess would be you've sprung a leaking your cooling system and you may have air in the system..

Do a pressure test on the radiator, if the pressure drops.. You sir have a leak.. Air in your system could quite possibly cause those symptoms

[XGTRX]

Just to share experience. A mate of mine had a similar issue and it ended up being a timing issue because he bashed the limiter a few times and the cas armature that connects to the cam had some slop in it and was changing the timing a few degrees. Gtr though.

[zoomzoom]

Sounds like you need to take a log of sensors with the consult cable. The change in rpm would correspond to some change in timing, air or idle control.

[Artic Choc]

Thanks for the replies. Il have a look at my rad pressure/ timing and see if i can log the sensors. Im heading back to tuner next weekend but anything i can do to fix it prior will have me a 2hr each way trip hopfuly

[scotty nm35]

It's usually lean idle that makes the revs fluctuate, as long as there are no vac leaks of course. Ask Trent on facebook, he would be the best person to advise you.

Smoke testing is a very hit and miss way of finding leaks, just pressure test the whole system to 30psi, then you will see how many leaks you actually have.