Engine: TD: 2.5 TDI fuel pump timing mark / base settings

[Turbodave]

I'll keep twittering away here...

But oh dear, we have issues. My gushing about how it seemed a bit less "nothing, nothing, nothing, ok go..." after it came back was a bit premature and I've now decided all is not well in my world. In fact I have several issues as it were.

1. Cold starting isn't very good - it used to fire up first time, every time but now it cranks for a couple of seconds and clatters into life, runs very rough for a couple of seconds and fires out a huge plume of whitish reek.

2. The power below 2000rpm is rather ****. At first I thought it seemed smoother but no, it's just lacking power. It used to plod along in 5th at 30mph whereas now it tends to labour. But what is more noticable is when I'm going up a long climb, I'm having to rev it out much longer as changing up, it will just die a death whereas before it's pull from almost bugger all rpm.

3. Fuel economy has sufffered. I used to brim the tank and I mean brim... and it's do nigh on 100 miles before the needle began to drop. Did the same on Friday, 60 miles later and it's already below the top mark on the gauge.

I want it to be right but it's not, it's just not as strong as it used to be and well, for the £100 spent getting the timing set... I'd kinda hope it would be right so tomorrow, need to make a call and take it back to have it rechecked and hopefully, sorted.

Bloody car...

[artiedtke]

If your 100% sure that the IP timing is spot on, I would begin checking out other things next like the MAF sensor and possibly the turbo control valve and associated vacuum lines.

However the three points you make are all directly related to bad injection pump timing. Maybe it has slipped (cant see how).

As you pointed out though, these cars are pretty gutless until you come on boost, it's only then they really begin to shift.

Keep us updated on any developments.

EDIT: Just read your previous message... bit confused... on the 20th you were saying it's great... so now it's gotten worse ?

[Turbodave]

Originally Posted by artiedtke

EDIT: Just read your previous message... bit confused... on the 20th you were saying it's great... so now it's gotten worse ?

Aye, I am contradicting myself a bit there.

When I first drove the car, it was warm and it was just around town as she'd just picked it up from the garage. It seemed like the turbo coming in was less obvious, yet it felt smoother and more progressive if that makes sense and all seemed fine.

Over the past few days I've done a few cold starts and noted it was struggling a wee bit and it's run very lumpy for the first couple fo seconds and kicks out alot of reek. I've also been suing it for the daily commute and there's a couple of stretches of road, one being a long steep climb after a second gear corner and changing into third, it just dies a death whereas before it seems to have a bit more low down grunt.

Plus, the fuel consumption does seem higher. I also found it amusing that when brimmed, it'd do 100 miles before the needle even moved... and as said, it'd done about 60 and it was already below the top mark. Same driver, same driving.

I've also just been up the motorway, car was hot and I gave it the beans down the slip road and it smoked hard in 4th, but continued to smoke into 5th. I figured it maybe just needed a good clear out as it's been town driving for the past few days so it's normal for it to be a bit smokey when it gets a kicking however, where it would smoke for the first wide open throttle run then be fine... tonight it was leaving a cloud of poisonous smog evenr time I opened it up.

It's not terrible, but I know the car inside out and whilst it's perhaps slightly smoother and perhaps has less diesal knock know... to me , I have this gut feeling it's overfuelling which given the symtoms above, would make sense. That and it smells quite strongly of diesel. There are no leaks, I checked but the exhaust smells strongly of diesel. Even she noticed.

So hence, gut feeling says it's over-fuelling...

[thetroublemaker]

OK.

First off I assume you took it to a dieseasel specialists? Therefore they used the bosch software to set the dynamic timing?

If so, you need to establish what temperature they did the timing at (it needs to be at 80 degrees coolant temp or higher) and what setting they set it to.

These engines use a fuel "map" generated by the ECU so the fuelling is more advanced at lower temperatures to allow slightly longer for it to be combusted in cooler situations, and more retarded as the engine reaches its optimum temperature.

This can be seen here on VAG COM (for the AEL / AAT variant of this engine used in the VAG product)



My gut feeling is that the engine was not set in accordance to the correct spec, or was lined up to the wrong part of the map - i dont know what the bosch software does.....

Either way I think 0.0 to -0.5 degrees when hot at the crank is about correct. This is 1/4 degree at the cam, so miniscule adjustments......Sounds over advanced to me....

[Turbodave]

Thanks chap...

The plot thickens and truth be told, I'm about 2 seconds from handing the keys to my local breaker.

The car's been a bit... dunno... just a bit dour for want of a better word but yesterday it started rattling, which I eventually traced to the tensioner on the diesel pump side.

The pointer itself was moving so far and so fast, it was rattling off the block. The pulley wheel was still spinning so no idea why the pointer was moving with such force and to an extent where it was hitting the block.

The plan was to take it back to the specialist today. So, started it this morning... no rattle. Had a look and the pointer finger is gone, as in completely sheared off. The exact same issue as the last one (though the last one had been on for years)

Thankfully it still runs, the belt is still tight but as to why the tensioner has failed - I do not know. I want to remove it and have a look at it myself, see if it's seized etc but given I never fitted it, I'll resist and send the car back to the repairer who set the pump timing - though to be fair, it could just be a defective tensioner.

Totally, totally fed up with this now.

[Turbodave]

And a small update...

Bought another INA tensioner last night. Locked up the pump, turned the cam shaft to pull the belt tight over the lower tensioner and then ignored all warnings of imminent death and removed the broken upper tensioner, fitted the replacement and tensioned it up.

"Oh noes!" they all cried "It'll be broken till it's broke" but on the contrary, it drives much smoother and pulls from way way lower revs, doesn't belch acrid black smoke on wide open throttle and this morning, rather than cranking and cranking then clattering into life with a massive cloud of smoke and a brief misfire, it started first turn of the key and idled perfectly.

So.... a) I have no idea what was causing the tensioner pointer to move with such venom that it sheared off and b) having changed it and perhaps altered the timing a bawhair in the process, the car's actually starting and driving much better.

Although should have it rechecked and set again but a) I'm loathed to fork out another £100 for the privillage and b) I'm half expecting this tensioner to do the same thing in a week or two.

Hey ho...

[RiPsTa33]

There must be somebody up there with volfcr, from what you've done yourself up to now I'm pretty confident you could do it yourself or even buy it which will be cheaper than £200 and then you can get ocd like me and check it every week ;-)
If you're ever down this way I'll do it for you.

[Turbodave]

Thanks fella... and yes, that's the frustrating thing. I would be happy to have a go myself as it's one of those kind of jobs that you're never quite sure if it's been done right - hence when I got it back, I wasn't convinced by the way the car was starting and running and having spent £100 on a wee man's time in the process, it's a bit of a bitter pill to swallow.

I have a copy of FCR but have since misplaced the lead plus I'm not sure if it's the correct version, think it needs to be a later version to check the timing but truth be told I haven't checked. I'll get another lead and have a look as it is something I'd happily do myself. My problem is I bought the car as a new comer to the diesel and figured that's how they are - but now, I'm sat wondering what is 'right' and if it's ever been right.

As said, I would say having fiddled last night it is actually better... even silly things, like driving work there's a long hill and before you could change up into 3rd and it'd pull ok, but after the timing was set... I was having to rev it out in 2nd so much longer or it's die in 3rd, but this morning it seemed to pull much cleaner from lower revs again. Plus as said, it started first turn with no smoke or lumpy running.

}Maybe it's a fluke or maybe I have just tweaked the timing that wee bit. Though there are still unanswered questions, namely why did the last tensioner start rattling after 3 weeks / 600 miles of use and was the timing actually right after it was set by the specialist?

Time will tell how it goes on but what I may do is run it for a week or so, source another cable and if possible get a suitable copy of FCR or make some enquiries and ask if anybody has a suitable diagnostic tool. I hate relaying on others for this sort of work - same as my other cars, a garage will read codes and do the basics and condemn the first part they can think of but very few will check further into things like mass air flow percentages, long and short terms fuel trims and 02 sensor maps.

So indeed, if anybody local (ish) has access to such a tool then I'd be very grateful if I could borrow it for an hour in lieu of some beers / external thanks!

[c70t5beater]

These are very sensitive to the timing being set correctly, i used to have a 850 tdi saloon. Ive seen the bosch and Vol fcr working and its really just tiny adjustments. On vol fcr there is a new and old belts tolerances and it have to be at least 80c water and 30c fuel temp. The vag com above is great program, my girlfriends polo tdi is running much stronger since i set it to upper limit of advanced.

Anyway, a friend of mine on here has full working version of vol fcr so will ask him if we can meet you in Port Seton or Tesco's at Forth road bridge and put you out of misery!

Brett

[Turbodave]

My tales of woe continue....

Following the last tensioner failure - ie it was moving to such an extent, the pointer was striking the block and subsequently snapped, INA decided it wasn't a warranty concern so that's that. I had bought a second, replacement tensioner and fitted it following the instruction to the T and all was well. I didn't get the pump timing tweaked, figured I'd run it a week or two to make sure all was well then spend money getting it done.

And, well... good move.

The replacement tensioner that was fitted has gone and done the exact same thing. It started rattling last night and about 5 minutes ago, it too snapped the pointer clean off as result of it vibration off the block. Granted, it's still tensioned and running but now minus it's pointer. Again.

So, christ knows what's going on here. That surely can't just be bad luck, there must be something causing the tensioners to a) move so violently and b) eventually fracture. I've checked everything, checked the pump moves freely, checked he cam, checked the lower tensioner and all appear fine so if anybody has any idea why this is happening, I'd be forever in your debt!

To recap, all fitted correctly and nut nipped up to the recommended torque and for the first week or so the pointer will move a couple of millimeters of it's mark as you would expect as the tensioner on the belt varies slightly. Then, after 500 miles or so the pointer starts moving to the point where it can hit the block - ie as it you were increasing the belt tension, thus the pointer is moving further anti-clockwise. But is doing this so quickly, you can't even see it move - it's just a blur / serious rattle.

Then it eventually snaps clean off.

This is seriously, seriously trying my patience now.

I need help!