Possible Vct Damage - How To Test Vct Operation?

[Dose Pipe Sutututu]

Howdy,

Probably get flamed for this but here goes.

2 Weekends ago, I attempted to do my RB25DET's timing kit (2nd time doing it, so not a noob). But this time on this particular R33, I've managed to 1. damage the harmonic balancer 2. possibly farked the VCT, I rattle guned it's mum to take off the nut as it was like welded on

Anyways, got a new balancer, etc. and now the car is running, but it runs like poo over ~5k rpm. It has no farking pull what so ever.

So, I've checked the timing markings (again) and they all line up 100%, the tensioner is done correctly and locked in (giving about 1/4 turn of the belt)

But the car still runs like poo, the CAS has been installed exactly where it was last marked (but I have yet to check the base timing with a gun).

I can hear the VCT clicking over, etc..but I'm not overly sure how it works. I'm concerned I screwed it using a rattle gun. On my previous R33 it came off with just a wrench, with this one it was like seized, so out came the rattle gun.

So is there any possible way of checking the VCT besides hearing it click?

[WMDC35]

power it up with the car running and see if it changes the idle

[Dose Pipe Sutututu]

good point, will disconnect it and then feed with +ve 12

[Adriano]

or you can fire the cam with a timing light to see if it moves

[GTSBoy]

The click is just the solenoid valve being activated. There's no telling what happens afterwards if you have managed to damage the actuator. So just applying or removing the power to it might give you the satisfaction of a click, but maybe it won't actually make the gear move.

You may need to put it on a dyno and check to see if the engine behaviour is any different with it connected or not connected. If you see no change at all, then suspect you broke it bad.

[WMDC35]

applying power at idle will at least tell if pulley is working, at those loads at least, if jammed on you'd notice power loss over 5500ish (sounds worse than that?), and idle would be a bit rough, so prob points towards cam timing? hopefully not broken locator on the cam for cas?

Edited June 11, 2013 by WMDC35

[Dose Pipe Sutututu]

The cam locator is good, it's the older type so there's a semi circle notch in there for the cas

I'll try the powering up and down and see if it moves the idle up and down.

I'm just hoping I didn't damage anything when I went full **** with the rattle gun. I know the service manual tells you to use an adjustable spanner on the cam itself but in the past I've easily removed it with a socket. I'm guessing the previous mechanic or owner loctite the thing on or rattle guned it's Mum on. Even the bolts on the water pump were torqued up so hard I needed a breaker bar.

[Dose Pipe Sutututu]

Does the Intake cam actually rotate an extra 10 degrees when the solenoid kicks over?

I'm curious on how it works, I know how other cam systems work such as MIVEC and VTEC but not entirely sure the RB motor uses the same concept.

[Ben C34]

the solenoid either opens or closes the oil flow to the vct, it doesn't directly move anything.

[Ben C34]

applying power at idle will at least tell if pulley is working, at those loads at least, if jammed on you'd notice power loss over 5500ish (sounds worse than that?), and idle would be a bit rough, so prob points towards cam timing? hopefully not broken locator on the cam for cas?

the cas goes on the exhaust cam, the vct is on the inlet cam.

[Dose Pipe Sutututu]

the solenoid either opens or closes the oil flow to the vct, it doesn't directly move anything.

I understand it flows oil in, but it must allow the oil pressure to move/rotate something to advance the intake cam or sprocket somehow right?

[WMDC35]

yes obviously, was just chucking possibilites for the power loss

rb just advances the cam timing, unfortunately not as fancy as vtec & mivec

the cas goes on the exhaust cam, the vct is on the inlet cam.

[Dose Pipe Sutututu]

Is there any chance I've actually overtightened the cam shaft onto the VCT cam gear/sprocket?

I've done some reading and apparently the inner part rotates back and forth allowing the cam to be advanced by 10 degrees or so when it is in operation.

I'll have a ticker and report back this weekend, hopefully it's silly like over tightening.

[WMDC35]

seems unlikely overtightening would stop it working but now there's drama would be good to torque it, to lose power up top from the vct it would have to be stuck on, you'd probably notice the idle & a bit of a different note from exhaust if that was the case so seems more like a timing issue?

[Dose Pipe Sutututu]

hrms...

I might pull down the lot again and check if the timing belt has skipped a tooth.. when I initially fired her up, I did notice lifter noise, but I was just under the impression that was because some oil leaked out when I pulled off the VCT cam sprocket to replace the cam seals.

[WMDC35]

yeah give it a good going over, sounds like it's losing more power than the vct would cause

[Dose Pipe Sutututu]

man last time I did this I didn't come across all these freaking issues

[SilverECR33]

its probably something else IMO - check everything you have touched.. and ps. always use a torque wrench for that sorta shit. however it is 123-130nm which is tight as hell for that big bolt, its in a keyway and not ment to move. Even so I doubt over tightening would do anything more than destroy your motor when the bolt snaps, its really those little ones are the ones u gotta be careful of over tightening.

Ps.. did you secure the cam when you tighted it?

[Dose Pipe Sutututu]

I nip it up then tightened it once I got the timing belt on and tensioned up, oh wells there goes my Saturday morning lol

[SilverECR33]

well, the reason you are ment to secure the cam, is so you do not bend a valve.