How Do I Know If My Vct Is Working?

[wrxxy]

Just wondering if anyone knows how to check and what checks to do , to see if the VCT is working on an R34gtt?

I have done searches but not very clear.

Thx In advance

[mad082]

as far as i know the r34 has constantly varying cam timing. i don't know if it is possible to check, but i'd say that if it wasn't it wouldn't drive as well as one that was.

[WogsRus]

you can check with cosults or pull the plug that ctivates VCT on the side, if it doesn't change the way the car drives, it's stuffed.

[infected flow]

you can check with cosults or pull the plug that ctivates VCT on the side, if it doesn't change the way the car drives, it's stuffed.

either that or put it on the dyno and have a look at the graph if there is a massive dip midrange then it aint working...

cheers

[GTS4WD]

if the car runs rough at idle..

Sounds like ass

seems like its lost power..

rough acceleration

then its not working

you could also unplug the VCT solenoid and see the difference..

[wrxxy]

Where do I find this plug and how to unplug it?

What does it look like as I have no idea where to find it?

Any help would be great.....

Thx

[GTS4WD]

Welcome to quite possible the bodgiest explination:

There is a solenoid near Cylinder 1 intake piping of the intake manifold, now I realise that there is a few there.. but this is the best pic I could find

On the turbo side of the engine there is an oil feed going to the head..

As soon as you acc. off idle (do this in neutral to hear it easiest) you can hear the VCT solenoid click on as soon as the car leaves idle

[wrxxy]

Thx for the pic but cant really see as pic is a bit blurry.....

[GTS4WD]

As soon as you acc. off idle (do this in neutral to hear it easiest) you can hear the VCT solenoid click on as soon as the car leaves idle

[RPMGTR]

Mmmm, close but not quite.....

The neutral switch dissables the VCT, so testing must be done with the car in gear.

34GTT VCT is a little smarter than R33, it needs x amount of throttle opening and rpm to activate.

It is switched, not infinitely variable as most assume.

As the VCT operation is not too dramatic, and masked a little by the small turbo, it is harder to pick by 'Seat of the pants' Dyno.

If not working or operating incorrectly, it can cause the cam timing to be retarded (more common, feels flat to 4500) or advanced (rough idle, feels flat past 5500)

Best way to diagnose is obviously on a chassis dyno.

cheers

Edited July 31, 2007 by RPMGTR

[wrxxy]

Thats my car feels flat till 4000-4500rpm!

I think it I will give Race Pace a call........