Check engine light, break up at cruising speed

[97vr4]

Hey fellas
My car has been nothing but smooth and awesome until yesterday
My check engine light came on, which it never has, and a short time later i started getting a stutter/missfire when at a cruising speed
The car seems to pull smlooth under any type of load or accelleration. Its when i stay at a steady speed it breaks up and missfires
If i get off the throttle for a sedond and then accellerate it will smoothen out but as soon as im not accellerating or under any type of boost it breaks up bad
Before the issue started, my head unit turned on and off a few times while driving and turns out the negative terminal was loose. All my grounds wires are attached to the negative post so i thought that would fix the problem. The car was still breaking up and doing the same thing on the way to work today
Local shop tried to scan the car last night to check the ecu code but due to it being from japan their scanner didnt pick anything up
Any help is appreciated and thanks in advance

[Nick Mann]

Check this thread out:
http://www.clubvr4.com/forum/showthread.php?70422
:D

[97vr4]

thank you,

[97vr4]

From doing some reading it looks as tho this is my issue
* Gearbox - this will appear as a drive train shudder in 4th or 5th at light to medium throttle. Backing off will solve the issue, but so will hard acceleration. Normally occurs at 30-40 mph.

[Humpty's Revenge]

From doing some reading it looks as tho this is my issue
* Gearbox - this will appear as a drive train shudder in 4th or 5th at light to medium throttle. Backing off will solve the issue, but so will hard acceleration. Normally occurs at 30-40 mph.

Change gearbox & transfer box oil

[Nick Mann]

This used to happen a lot on old dexron 3 fluid. Our boxes really shouldn't be run on that. It is much easier now to find sp3 compatable fluid though.

My understanding of the gearbox shudder is that the clutch packs glaze because the old oil has incorrect slip properties. Changing the oil brings the slip properties back to where they should be, but how long it takes the issue to completely clear depends on how badly the clutch packs are glazed and how good your new oil is at helping to clean them. Often an oil change is an instant fix, but not always. It's cheaper than taking the box out though!!

[elnevio]

As far as I know, Amsoil ATF is the only SP-III compatible fluid that will actually improve such a tarnished gearbox, so I would be doing a full flush with it, and then running it for a good few thousand miles before replacing the fluid again.