VARIABLE VALVE TIMING UNIT

Submitted by yorkie on

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Hi guys. I'm new to the forum but this post is one of the reasons for me joining.
I have a Y reg Sirion 1.0 litre automatic with the twin cam 3 cylinder engine.
I gather this engine has a variable valve timing system.
The engine was running fine and is fairly low mileage but conked out with a bit of a rattle and would not start again.
I have done the usual checks, there is fuel to the injectors, there is a spark to the plugs and the timing belt is fine and the marks on the pulleys line up as they should.
However, when I turn the engine over by hand and watch the cam shafts, the inlet cam is way out of sync with what should be happening.
I suspect the hub unit that the exhaust cam shaft runs through drives the inlet cam but it's as if it has slipped round out of timing with the exhaust cam.
I have got the cams out and the hub unit off the exhaust cam but can't get it apart as it has four unusual headed bolts holding it together.
Any clues what is inside this unit (it feels like some sort of clutch affair) and are they known to fail.
Also how do you set these cams up timing wise when reassembling them.
Hope someone can help.
Chris

I don't think yours has

Submitted by Pocketrocket on

Im not sure yours has variable timing, I maybe wrong but with the Cuore (same engine) the Variable valve timing version came in 2001.

Sounds like the timing belt could have jumped. Although the bad news is that the engine is a interference type so the pistons may have hit the valves.

I have the engine workshop manual on CD which will likely help you out!

From what I gather about the

Submitted by Pocketrocket on

From what I gather about the variable valve system Daihatsu use. The unit is controlled by oil pressure. Rather than any electronics

Thanks Pocketrocket. The

Submitted by yorkie on

Thanks Pocketrocket.
The timing belt is fine and the timing marks are where they should be.
The front camshaft (the exhaust one) is driven direct by the cam shaft pulley but it has a hub unit just inboard of the cam shaft pulley, which the exhaust cam runs through. This hub unit drives the back camshaft (the inlet one) via gears. This hub unit appears to have an internal mechanism that somehow adjusts the drive to that inlet camshaft and that is what I need info on i.e. how do you get it apart and how are they set up and timed when re-assembling.
In your CD manual, is there any mention of hub/drive unit that the exhaust camshaft runs through?
Chris

EJVE engine looks to have a

Submitted by DaihatsuDave on

EJVE engine looks to have a VVT unit to me and is similar to the 1 ltr Yaris...maybe the same??
Some of the yaris timimg chain kits have a VVT unit in them.

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Thanks guys. Yes I believe my

Submitted by yorkie on

Thanks guys. Yes I believe my engine is the EJ-VE and I gather there are some similarities with the Toyota unit.
Yes I get the impression this VVT unit/hub is operated by oil pressure. There is a oil feed pipe up to a valve above the exhaust camshaft and oilways appear to go through the cam to the centre of this hub unit.
I was just hoping for some detailed diagrams of what's in this hub unit, how it's supposed to work and how it is set up initially with regards to timing the inlet cam to the exhaust cam. The position of the exhaust cam is determined by the timing belt and traditional timing marks so that's easy. It's just knowing how the inlet is timed through that VVT hub unit and the gear that drives the inlet cam.
Has anyone got a manual with good diagrams and the cam timing procedure?
Regards,
Chris

Hi again guys. I've just been

Submitted by yorkie on

Hi again guys. I've just been googling some youtube videos of the Toyota VVT systems and I'm pretty sure this hub unit just has a vanes asembly inside. Four vanes attached to the hub outer casing and four attached to the hub centre boss that is keyed to the exhaust camshaft. Oil pressure then fills the four cavities between the vane sets pushing them round by about 25-30 degrees to advance or retard the inlet cam that drives off the outer case of the hub unit.
I suspect on mine the vanes may have sheared off and the hub unit outer case is being allowed to turn further than it should.
Once I've got the end plate off (funny headed bolts holding it on) I may know more.
Regards,
Chris