Technical How many teeth can a 1.9 jtd 8v cam pulley be off?

[ruispeed3d]

Hi guys,
while changing the timing belt on my 1.9 jtd 8valve i noticed that the original cam pulley timing slot is off by one tooth compared to the pointer arrow on the block. the slot is one tooth to the right of the engine pointer arrow(if you look at the pulley straight ahead).

I don't know if that's advanced or retarded.

i never changed the timing belt on this car but haven't noticed anything wrong.

Should i revert it back to the specified allignment? how many teeth can this engine be off by(camshaft wise).

Thank you

 

[Davren]

It shouldn't be any teeth off, it should be exact. Did you use the tool to lock the crankshaft sprocket while replacing the belt?
.

 

[bugsymike]

Hi guys,
while changing the timing belt on my 1.9 jtd 8valve i noticed that the original cam pulley timing slot is off by one tooth compared to the pointer arrow on the block. the slot is one tooth to the right of the engine pointer arrow(if you look at the pulley straight ahead).

I don't know if that's advanced or retarded.

i never changed the timing belt on this car but haven't noticed anything wrong.

Should i revert it back to the specified allignment? how many teeth can this engine be off by(camshaft wise).

Thank you

Not sure which engine code yours is , but my old Autodata book shows a tool on crank pulley aligning crank and underlines the importance of keeping the belt taut between sprockets on the non tensioned side. i.e. from camshaft pulley down around guide roller and a round the crank pulley, if you have done that and the tensioner is correctly set and then after gently turning the engine over by hand at least two full revolutions, if it still is misaligned I would query the quality of cam belt.
If the camshaft pulley is slightly forward of it's clockwise direction, I would think the valves would open slightly early.
It may be possible by putting the belt around the cam pulley, set just before the correct timing mark that as you take up the little slack from there down around the guide and around the crank pulley it removes any slack on that side of the belt so that with it correctly tensioned after turning clockwise the engine at least two full revolutions that it gets to the correct timing position.
As with any timing belt fitting follow instructions carefully and I personally always turn the engine over by hand several times before firing it up. I have known garages not to follow that and cause thousands of pounds of damage on nearly new vehicles!

 

[ruispeed3d]

It shouldn't be any teeth off, it should be exact. Did you use the tool to lock the crankshaft sprocket while replacing the belt?
.

Yeah I used the locking tool but what happened is I used another timing mark on the cam pulley that someone had painted and that aligned with the crank locking tool but this mark is almost opposite to the cam pulley original mark.

I changed the belt focusing on that mark and did it with no effort and the mark was still alligned.
But as I turn the engine a couple times I notice that the mark I used stayed timed properly but the original mark was always off by one tooth.

I'm currently timing the engine according to the original and I'm about to turn it by hand to see if nothing interferes, if you know what I mean

 

[vexorg]

Weird, we had a 1.6 Tipo years ago, the timing was out by 1 tooth when changing the belt before taking it off. Set the timing correct to the marks and it ran like a dog, so slow and gutless. Then changed it back to the wrong timing and it ran perfect again.

Always put it down to fiat just being weird and eccentric. And no real surprise when I found the new engines dont even have timing marks!

 

[ruispeed3d]

Weird, we had a 1.6 Tipo years ago, the timing was out by 1 tooth when changing the belt before taking it off. Set the timing correct to the marks and it ran like a dog, so slow and gutless. Then changed it back to the wrong timing and it ran perfect again.

Always put it down to fiat just being weird and eccentric. And no real surprise when I found the new engines dont even have timing marks!

Thank you for your input.

well that's a weird symptom, i have no ideia why that happens but it can just come down to the way the engine runs, i've always heard of advancing or retarding the timing to gain performance but i've always thought that could only happen on performance engines or race engines but could easily still be the case on your engine.

 

[ruispeed3d]

Hey everyone,

Just wanna update on this situation and thank you all for your input.

I've decided to put the engine back to it's original timing marks. Positioned the engine to use the crankshaft locking tool and aligned the cam pulley notch with the engine arrow mark, then proceeded to put in place the belt and tension pulley(the rest was already installed, wp and guide roller).

I rotated the engine carefully by hand 2 times just to be sure the marks still aligned and the internals didn't collide but it all looked good and i then proceeded to start it. It started perfectly.

I still haven't stressed it too much but went for a ride a couple times and it looks like the engine runs definitely better, especially after changing into a higher gear. Before it always had a little rpm pit or, i think you can call it, turbo lag just as i started to accelerate again but now that window is shorter and in consequence the engine is more alive right after i change gear.

Just wanna had that in this process i ended up restoring my high pressure fuel pump(since i can only remove it with the timing belt out) because it had a fuel leak on one of it's compression cylinders. I'll just try to post as many photos of the hole timing belt and pump process so you can see how it looks on the inside and hopefully encourage someone who needs to do something similar.

It isn't a completely straightforward job but at the same time it wasn't an intimidating hassle. You can easily do it if you put your mind to it and search how it's done.

Parts fitted:
DAYCO KTBWP3170
MEAT&DORIA 9155 complete high pressure fuel pump seals kit

P.S. I can send every picture and information i have to anyone of you if you want, ask for it if someone wants it.

 

[bugsymike]

I have stripped and rebuilt some Bosch common rail injectors, not to diesel specialist standards but certainly so it ran happy with good emissions but I have never had the need to open up an injector pump like these. The last time I did was an inline CAV pump as an apprentice at college 52 years ago, impressive

 

[Ralf S.]

That's interesting.

My JTD always had a problem aligning the mark on the pulley with the pointer on the head. On mine the mark on the pulley was always slightly left of the mark. It also seems that someone once tried to tighten the pulley with the mark held over to the right, which of course isn't possible because the key on the back of the pulley is supposed to fit into a slot on the cam-shaft.. and so tightening it up with the key not completely in the slot broke off a piece of the key on my pulley, so then it had even more "float" in it.

This "float" did let me rotate the pulley clockwise so that the cam pulley finally aligned with the mark.. but when I started the engine it really wasn't as happy as with the mark in the original position (that is, the pulley and the mark were about half a tooth out) so I tended to leave the timing exactly as it came off, even though the marks didn't line up.

I did eventually buy a new pulley with an intact locating key and the mark on that new pulley lined up better with the mark on the crankcase, but still not perfect. Obviously the mark on the head is actually just moulded onto a piece of plastic, so it could be deformed slightly... I gave up worrying about the marks and now just lock the crank and as long as the camshaft doesn't move, pretty much just fit the pulley back onto the camshaft 1/4 to 1/3 of a tooth out.

I dunno what happened to yours.. since the key on the pulley should prevent anyone fitting the pulley 180 degrees out, as your photos appear to show? But the slot on the camshaft might go all the way across (I can't remember) so it's possible someone fitted the pulley "upside down" in the past... but then the TDC sensor would "miss" the timing slot (your picture 6) and the injection would be 180 degrees out too... so I'm confused.

Anyhow, if your crank is locked and the pulley is lined up "more or less" with the pointer mark on the head/plastic then it'll run. If it's a whole tooth out, the car will rev "lumpy" so you can tell straight away. Just rotate the pulley into the centre of any "float" it has on the camshaft... and it'll probably be in the right place, even if the marks are 1/3 of a tooth out.


Ralf S.

 

[vexorg]

I've had a few cars wit the timing out by one or two teeth, tends to be sluggish and underpowered rather than lumpy