Autospeed article on PD injector timing tune

[buzuki]

haha yeah, im aware of it.

But, have not had to make adjustments. Obviously some people have had issues with it. But, when a new belt goes on it would set the cam postion directly back to original position. if the belt is worn and your car is going better, it would suggest the timing is incorrect from factory right . . .

The only reason for adjusting would be discrepancies in the new belts, (shorter/longer) but this length you have to imagine would be marginal.

[gldgti]

haha yeah, im aware of it.

But, have not had to make adjustments. Obviously some people have had issues with it. But, when a new belt goes on it would set the cam postion directly back to original position. if the belt is worn and your car is going better, it would suggest the timing is incorrect from factory right . . .

The only reason for adjusting would be discrepancies in the new belts, (shorter/longer) but this length you have to imagine would be marginal.

as far as i'm aware, every 4 cylinder vw diesel since the first ever (and certainly every one i've owned - 1.5D, 1.6D, 1.9D, 1.9TD, 1.9TDI from the 90's and now 1.9TDI PD) has a timing belt change procedure that includes adjusting the cam timing as a matter of course - its just part of what you do - set crank at tdc#1, set all the locking tools, loosen cam sprocket, put the belt on, check crank at tdc#1, tension belt, check tdc#1, check tension, tighten cam sprocket.

doing it that way is the only way to ensure that its correct - because with all the locking tools in place, if the cam sprocket cant rotate, then when you tension the belt theres no way for the tension to equalise all the way around, and the crank will always move (even if only a little bit).

The result is that unless you do the procedure including adjusting the cam sprocket, you cant be certain that everything is perfect... might be close, but not perfect.

[Buller_Scott]

after my timing belt my car felt quite sluggish in the top end, the 'powerband' had shifted. (yes... i double checked everything was TDC!) So the next day I advanced my cam timing to the max (which wasn't much from where it was already). Started first time, bang on!

Now goes like a cut cat and boosts 4psi harder. Win.

was the engine out of the car for all of this, josh? as far as i understand things, timing belt job is an engine out jobbie, but the actual timing advancement / retardation can be done simply by loosening the 3 bolts, then rotating the pulley?

or did you have to have pulley / sprocket locking tools in place before changing the timing / rotating the cam pulley?


EDIT: i just read the article about cam timing adjustment on pd engines as provided by brad in julian edgar's original thread on here, so please pardon any double ups in questions.

here's one that might be interesting, though: i have a handset with 3 different maps: stock, road, and track.

road map has the greatest torque of all 3, with the dyno showing torque to come in lower in the rev range. track map, however, has greater power (obviously) higher in the rev range, with less torque than the road map, and that torque peak coming in higher in the rev range than with the road map.

would adjustment of the cam timing in either map, result in pushing (for example) the torque peak higher in the rev range, and the power peak higher still? (if that makes sense).

what would your suppositions be, gurus?

[buzuki]

as far as i'm aware, every 4 cylinder vw diesel since the first ever (and certainly every one i've owned - 1.5D, 1.6D, 1.9D, 1.9TD, 1.9TDI from the 90's and now 1.9TDI PD) has a timing belt change procedure that includes adjusting the cam timing as a matter of course - its just part of what you do - set crank at tdc#1, set all the locking tools, loosen cam sprocket, put the belt on, check crank at tdc#1, tension belt, check tdc#1, check tension, tighten cam sprocket.

doing it that way is the only way to ensure that its correct - because with all the locking tools in place, if the cam sprocket cant rotate, then when you tension the belt theres no way for the tension to equalise all the way around, and the crank will always move (even if only a little bit).

The result is that unless you do the procedure including adjusting the cam sprocket, you cant be certain that everything is perfect... might be close, but not perfect.

Yep thats pretty much it. Similar to the 2.0l current tdi's also, except now you also lock the pump and loosen the pump pulley. They even allow a 5mm margin.

[gldgti]

the old VE pump diesels (70's - early 2000's) also had various pump locking tools, depending on whether the pump was adjustable in the pump bracket or the pump sprocket was adjustable.

[GoLfMan]

was the engine out of the car for all of this, josh? as far as i understand things, timing belt job is an engine out jobbie, but the actual timing advancement / retardation can be done simply by loosening the 3 bolts, then rotating the pulley?

or did you have to have pulley / sprocket locking tools in place before changing the timing / rotating the cam pulley?




EDIT: i just read the article about cam timing adjustment on pd engines as provided by brad in julian edgar's original thread on here, so please pardon any double ups in questions.

here's one that might be interesting, though: i have a handset with 3 different maps: stock, road, and track.

road map has the greatest torque of all 3, with the dyno showing torque to come in lower in the rev range. track map, however, has greater power (obviously) higher in the rev range, with less torque than the road map, and that torque peak coming in higher in the rev range than with the road map.

would adjustment of the cam timing in either map, result in pushing (for example) the torque peak higher in the rev range, and the power peak higher still? (if that makes sense).

what would your suppositions be, gurus?

nope the timing belt isn't an engine out jobby, you just have to take out most of the drivers side of the engine, including the engine mount. Only took about 3 hours with help from an experienced hand

in regards to pully position and 'powerband' shift. Yes it will effect it. The further advanced you go the higher in the RPM range (and from what I found, more boost and more smoke) the power goes. Its quite interesting really!

[Buller_Scott]

sht yeah its interesting. i read in the article on autospeed that adjusting the timing can increase fuelling / duration, i wonder if this results in somehow the turbo trying to provide more air to meet the extra fuel, without there being more requested boost in your custom code map?

also, i noticed that the preferable way (as far as i could gather) to adjust the timing would be to adjust the cam gear pulley, as opposed to the cam sprocket?

would there be any foreseeable disadvantage to adjusting the cam sprocket with a wrench, instead of the cam gear pulley?

cheers

[Rob Burns]

That's the correct way to adjust the cam timing. Basically the belt is installed to the sprocket with the 3 smaller bolts loosened off and then the cam is adjusted until it's locator aligns with the one on the cylinder head. If the cam needs to move more than the allowed space (which is equivalent to 3 teeth on the belt) then the sprockets needs to be moved.

[Buller_Scott]

ah, so if one was experiencing rough idle and a slight hesitation on start up, and wanted to adjust the timing, they'd be better off to make the timing adjustments by way of using a sprocket counterhold in the holes on the sprocket, rather than turning the 18mm center bolt with a wrench in the following pic?

[Rob Burns]

No, as the cam sprocket is directly timed to the crankshaft it is a million times easier to turn just the cam (ie:18mm bolt) than the sprocket.

In that picture you have posted it would be impossibly to move the cam because the locking pin is locking the cam (not the sprocket) to the head. The black ball is the locking tool btw. There should also be a locking too on the crank that locks the crank to the block.

It's quite hard to describe the way it works when not in person.

Having said that I would not be touching cam timing to try and fix a rough idle or slight hesitation on start up. Any chance your engine is a BKD?