200tdi TDC markings not consistent

[youngengineer]

I've just rebuilt the injection pump on my 200tdi. I used a dial indicator to time up the pump to 1.54mm of lift at TDC (locked the pump, reinstalled the pulley flange so that it lined up with the timing pin hole in casing) then fitted it back onto the vehicle, locked the flywheel with locking pin, removed the pulley support tool and tightened up the pulley locking plate.

Although it started first time (after bleeding lines and pump) The first start and run the engine is noticeably more knocky and noisy. The timing sounds far too advanced.

 

I have installed the flywheel locking pin again to check the timing and have noticed that the TDC markings on the front pulley do not line up with the webbing/gusset on the timing cover and are off a few degrees even though the flywheel locking pin is in? I have indeed confirmed that the flywheel locking pin is engaged as it is sprung loaded and clicks into place when the engine is turned over. Removing the pin once engaged shows the timing slot in the flywheel.

I know that there are two timing slots on the flywheel, however I believe they are quite far apart? The pulley markings show only a few degrees deviation. 

Does anyone know how this could be possible? Has the pulley spun the keyway or is something else going on?

Any advice welcome.

 

 

Edited March 5, 2022 by youngengineer

[western]

Are you using the narrow slot in flywheel? 

Have you had the big nut in middle of injection pump shaft undone? 

[youngengineer]

The Injector pump was fully stripped and rebuilt so yes the big nut was off. But it was retimed according to the service manual. I still don't see how that would have an effect on the crankshaft pulley TDC position relative to the flywheel TDC mark.

Edited March 5, 2022 by youngengineer

[western]

Only way the crank pulley can move is if the woodruff key is chewed up & been over ridden by the pulley. 

I would get the crank & pump timed up & remove the pulley to inspect the crank nose & woodruff key & it's slot in crank & pulley. 

[Eightpot]

Only set tdc with the flywheel slot, ignore the cast web other than a rough guide.  You need to set the pump lift with pump on the engine so you can match it with engine tdc ideally - but you must be pretty close, sounds like its a little advanced, if you've got enough play on the sprocket slots I'd just adjust the pump spindle to retard it till it runs nice. I usually add a little advance anyway. 

[youngengineer]

Thanks for the replies. I adjusted the pump ever so slightly and it's now sounding normal again so must be been off by a hair.

 

As for the for the front crank pulley I'm going to remove it and have a look at the keyway.

[youngengineer]

Took the front pulley off and the keyway and Woodruff key look perfect so I'm at a loss on why the timing marks don't match.

 

Edited March 5, 2022 by youngengineer

[western]

Nothing wrong with the keyways & woodruff key, don't think there is much else you can do, 

only other thing I can think of if if the flywheel has been fitted incorrectly to the crank, 

[Peaklander]

What was the alignment like before you removed the injection pump? Did you move to TDC and then clamp the pump pulley or not bother and do it at refit? I presume it was the latter, hence the ‘problem’.

Edit. I realise though that we are talking about both ends of the crank - so it can’t change!

Edited March 6, 2022 by Peaklander

[hurbie]

turn the cranckshaft so the woodruf key is at exactly 12 o'clock , then your timing pin should slot in the flywheel ... if not , the flywheel is mounted incorrect (might be missing the locator stud) 

[youngengineer]

That's a good idea. I rebuilt the engine around 2 years ago so it's very possible that the flywheel was not re-installed correctly. I did not know that the dowels could be removed. Either way, if it is misaligned at the flywheel, I should probably be timing the engine with the mark on the front pulley. It would also mean that I have had it incorrectly timed for the past 2 years as I used the flywheel timing pin.

 

I've got it sounding pretty and running well at the moment so maybe I will just leave it.

[Sigi_H]

Many years ago I had exactly the same prob with my Yamaha XS500. I always wondered, why it is so slow. TDC Mark did not correspond with TDC. But it only affected the ignition. I made new exact marks and everything was ok.

This problem seems not to be uncommon.

 

[Snagger]

It’s not impossible that the flywheel or its housing was made with an incorrectly aligned locking tool aperture, or that the bolt and dowel holes in the flywheel or crank were drilled misaligned.