Timing the TDI. |
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Baxter
Admin Group Scruff Daddy Joined: 29 May 04 Location: Huddersfield Status: Offline Points: 8060 |
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Posted: 20 Oct 07 at 23:16 |
This applies to 2.5 TDI models, 88, 102 and 151 hp models 1996 - 2003. This is not a how to, this is not a blow by blow account, just a page of notes on some pitfalls that you are likely to encounter. Chances are your garage will do this work for you, after reading this you should have a pretty good idea of what is involved and what to quiz your garage about to gain confidence in them, and, more to the point for you, the owner/driver to feel like you know whats involved so it feels like your getting your monies worth when you get your bill! The engine is TDI, Turbo Direct Injection. This IS NOT for 2.4D To achieve lower exhaust emissions, good economy and good power output these engines are completely computer controlled. The electronic governor is an output of the ECU (Engine Control Unit, basically a computer) and it's output is determined from several inputs into the ECU including throttle position, air flow into the engine, engine temp, ambient air temp, boost pressure and temp etc... Obviously, this precise computer control requires an above average level of service when it comes to cam belt change or pump replacement. The service interval for the cam belt (timing belt) is 80 000 miles. Although it is prudent to change them early as if they do fail chances are it will destroy the top end of the engine and you risk piston damage. When replacing the timing belt it is recommended that you change both timing belts (the injection pump has it's own drive belt, separate to the main cam belt) all the tensioners, the idler pulleys, the water pump and the crank shaft pulley bolt as well as the rocker cover gasket. Shopping list.
That lot above will set you back around £200 from a VW main dealer. The timing belt. As per just about every other VW Diesel, the cam pulley is wedge mated, it is infinitely adjustable. Okay, there are a few ways of setting this up. On the pump pulley, should be a mark that corresponds with a mark on the pump body, or bracket, thats number one, make sure it is. Fit your belt, tensioner and idlers. Nip up the cam sprocket. **Never, ever turn the engine with the belt connected with the wedge/plate removed from the pump, you will break very expensive... er... things)** Now.. You should be somewhere near now, and it will probably run but... The injection pump needs to be set into such a position so that one of the actuators in the injection pump has enough leeway to adjust the timing backwards and forwards to achieve economy, smooth running, low emissions and power. This means a "basic setting" has to be carried out. The old school way. If you have messed around with VW Diesels before chances are that you will be familiar with a DTI (Dial Test Indicator) You fit the DTI to the back of the injection pump through the timing port via a threaded adaptor that fits between the injector pipes in the pump head.
If the measurement in more than .55mm the timing is too far advanced. If the measurement is less than .55mm the timing is retarded. To adjust the timing you do the following.
Once you are happy that the basic position is set, make sure all pulleys are tight, and the pump lock set to unlocked. Test engine. Now this works, to a degree, this figure [.55mm] was set on a new engine, but using this method I have found that the pump has had to be set as far as .7mm lift @TDC to achieve what I am meant to when diagnostic equipment is used. A few ways of checking with diagnostic equipment.
VagCom timing checker. If you have VagCom, there is a plug in (supplied with latest versions of the software)
Just reading off what VagCom says.
You will now get a list of numbers, in the second box should be 55, or there abouts, thats your pump timing. If it's not, over 55 is advanced, below 55 is retarded.
Another way
This shows.
Now, I need to check these parameters but, from what I have read.. If the actual timing is between .5° and 2° and the duty cycle on or below 10%, everything is cool. I will update this method when I can find out a bit more about it. Adjusting the timing. It's properly hard to get it bang on, it takes a fine hand and a bit of practise, again, make adjustments by tiny movements on the cam pulley for the injection pump. You can either undo the bolt and move the pulley in relation to the cam to get it near or use the idler pulley and the tensioner pulley for smaller adjustments. Link to VagCom from Ross Tech
Edited by Baxter |
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Baxter
Admin Group Scruff Daddy Joined: 29 May 04 Location: Huddersfield Status: Offline Points: 8060 |
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I'll finish it another time, too late! Too drunk!
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jemster
Not Quite Newbie Joined: 14 Nov 05 Location: United Kingdom Status: Offline Points: 25 |
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Glad you've got all that nicely worked out as I think you'll be having some practise on mine when it comes in. By the way I found one of the wires to N75 completey worn through, so no circuit hence not boost . Ive bodged a repair to the wire but now get loads of smoke and the sound of escaping boost pressure . Roll on 2nd November and my vans appointment with the doctor!
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Baxter
Admin Group Scruff Daddy Joined: 29 May 04 Location: Huddersfield Status: Offline Points: 8060 |
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Updated. More to follow.
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Baxter
Admin Group Scruff Daddy Joined: 29 May 04 Location: Huddersfield Status: Offline Points: 8060 |
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Edited, and updated.
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jets
Groupie Joined: 31 Dec 06 Location: Australia Status: Offline Points: 143 |
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Excellent write up, one of the best I have seen. A couple of suggestions.1 Could you go into some detail on the timing belt replacement end. eg Did you have the special tools or make them. I have ordered the 32mm special ring tool to adjust the tensioner but will need to make the holder for the bottom pulley. 2 I would add a crankshaft seal to your shopping list.Please keep adding to your procedure as you learn more or receive more info.
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Baxter
Admin Group Scruff Daddy Joined: 29 May 04 Location: Huddersfield Status: Offline Points: 8060 |
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Special tools? I run a garage, I already have them. You only really need the flat bar for locking the cam.
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Baxter
Admin Group Scruff Daddy Joined: 29 May 04 Location: Huddersfield Status: Offline Points: 8060 |
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Edited, more added. |
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Tr1cky
Groupie Joined: 17 Oct 07 Status: Offline Points: 53 |
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excelent tool / post !
any chance of the non turbo ? 1.9 and 2.4d :) 2.4 1st as I have mine in pieces Rich |
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Baxter
Admin Group Scruff Daddy Joined: 29 May 04 Location: Huddersfield Status: Offline Points: 8060 |
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They are a piece of piss, and covered by those copied manuals on e-bay It's kinda similar, time it up on number 1 before you pull anything off. Fit lock to injection pump sprocket. Remove injection pump belt cam pulley and fit locking tool. Remove timing belt. Make sure engine is on number 1 through the spy hole in the bellhousing, fit belt, tension belt, turn engine twice by hand, recheck timing and belt tension. Swap injection pump belt, remove cam lock and fit pulley. Fit DTI to pump, turn engine backward till gauge stops moving. Set DTI to zero. Turn engine to TDC, read DTI, if incorrect then crack off pump belt cam pulley and move to such a position where timing is correct. Again, turn engine backwards till DTI stops, check it's on zero then back up to TDC and read gauge. Not 100% off the top of my head but I do think the timing is .55m lift at TDC same as the TDI.
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jets
Groupie Joined: 31 Dec 06 Location: Australia Status: Offline Points: 143 |
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Edited by jets |
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Baxter
Admin Group Scruff Daddy Joined: 29 May 04 Location: Huddersfield Status: Offline Points: 8060 |
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It's about £50 from VW. You are meant to torque the new bolt, then turn it 180°. It's fairly normal practise in garages to torque it, mark the bolt with paint then use the air gun to get the 180°. Edited by Baxter |
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Tr1cky
Groupie Joined: 17 Oct 07 Status: Offline Points: 53 |
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oops ! - mine is in bits already and I didn't lock it a number 1 anyway - my head is foobared so it dont matter much at the moment ! |
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