z/e 16se engine timing belt tension troubles.

[Andy]

I have a z16se bottom end mated to an e16se head and recently done an engine rebuild.
Having problems timing the thing up,have both marks lined up,fit the belt and tension the water pump.It is the non tensioner type with the smaller 104 toothed belt.Turn over by hand and the marks are off,bottom pulley on the align mark but top pulley is half a tooth behind.
It is possible to put it on and it be tensioned as it should be,however it ends up half a tooth out every time.
Any ideas?
It has been running,just misses and I was checking over everything,thought this may cause that

[bazil]

Can you not just run the longer belt and tensioner?

[Andy]

the tension problem is between the top and bottom pulley,the long bit of the belt.It flops about like a soft knob,to eradicate this means setting it half a tooth out if that makes sense? I don't think the auto tensioner would solve it???

[Adam]

Cant you just play about with the water pump position a bit to get the belt tension right?

Are you timing the bottom end up off the bottom sprocket? Or the alt belt pully?

[Andy]

crank pulley mark.
tried that to no avail ends up half a tooth out.
almost like its the wrong belt.
id run a vernier but class rules prohibit their use

[bazil]

The tensioner does help,

You set the tension between the crank and cam on the belt ( set on the marks )
Then between the cam and water pump ( rotating the pump if required )

The tensioner takes up the slack between the water pump and crank

Edit, if your loosing tension between the crank and cam then check your head, has it been skimmed a few times and needs a thicker gasket?

[Andy]

its skimmed to the limit but i wouldnt have thought a mil would make the difference it is

[mowgli]

andy, you will have advanced the cam timing by the skimming, and I don't think you'll be able to time it any better than you have. the only way to sort this out is by physically measuring the real timing of the crank & cam, then moving the timing pin hole on the back of the pulley.

[Andy]

thanks mike.so in addition would you just go for what iv done which advances half a tooth but opoduces good tension?
the misfire is still present,the pipe clamped caused it to cut out almost re last nights pms

[mowgli]

when its warm, it should idle nicely with the pipe clamped.(which mimics the icv working), when its cold, it should idle faster, and this is done by a combination of the icv opening & the cts working to send a bit more fuel, if its nearly cutting out in idle when cold, its most likely had the 'mixture' and 'idle' screws turned down, which is usually done to mask another problem, ie. an air leak, the icv not working etc.

this all depends on the dizzy timing being set correctly. use the Haynes method (shorting out the throttle pot wires) then remember to retard it a couple of degrees for unleaded.
the cam timing being out by a couple of degrees and the high compression will make it run lumpy anyway.