Jump to content
SAU Community

Recommended Posts

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?

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.

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 by WMDC35

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.

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.

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.

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?

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.

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?

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.

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?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I came here to note that is a zener diode too base on the info there. Based on that, I'd also be suspicious that replacing it, and it's likely to do the same. A lot of use cases will see it used as either voltage protection, or to create a cheap but relatively stable fixed voltage supply. That would mean it has seen more voltage than it should, and has gone into voltage melt down. If there is something else in the circuit dumping out higher than it should voltages, that needs to be found too. It's quite likely they're trying to use the Zener to limit the voltage that is hitting through to the transistor beside it, so what ever goes to the zener is likely a signal, and they're using the transistor in that circuit to amplify it. Especially as it seems they've also got a capacitor across the zener. Looks like there is meant to be something "noisy" to that zener, and what ever it was, had a melt down. Looking at that picture, it also looks like there's some solder joints that really need redoing, and it might be worth having the whole board properly inspected.  Unfortunately, without being able to stick a multimeter on it, and start tracing it all out, I'm pretty much at a loss now to help. I don't even believe I have a climate control board from an R33 around here to pull apart and see if any of the circuit appears similar to give some ideas.
    • Nah - but you won't find anything on dismantling the seats in any such thing anyway.
    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
×
×
  • Create New...