D5252T ('96 850 TDI) Dynamic Pump Timing - any tips?

[Volvostudent]

Hi all,

..surprise surprise the dynamic injection pump timing on my 850 TDI needs doing! my friend managed to borrow the pump timing software which shows it at -6.0 degrees (thanks to artiedtke for the advice on the cable in my other post - the cable seems to work fine, albeit with the occasional connection dropout, perhaps due to weakish battery in car..)

As he's a mechanic he's going to change the injection pump timing belt this week, I just wondered if anyone knows of any tutorials or guides around to do it..?

My friend's never changed one on a Volvo before, so will be consulting autodata (steps probably similar to as I found here):

http://www.justanswer.com/uk-car/3ro...-injector.html)

and as many D5252t owners will attest to even many garages don't know how to set them up properly themselves!

Although I've never done anything like it before I'm ok with car basics, and would like to get as much of it done myself as possible, under his supervision of course. so any tips and pointers for a novice greatly appreciated..

Also if anyone has any experience of using a non-Volvo belt and pulleys from eg Euro car parts, are they of good enough quality (e.g. Continental make etc.) or should I absolutely stick to original Volvo parts for this job?

Cheers!

[Galaxie390]

Hi,

All praise to the tdi font of knowledge that is Artiedke ; )

He's a really helpful guy, and gave me loads of adivce and walked me through the timing changes on my own tdi.

You probably know already, but larger changes need to be made by loosening off the camshaft pulley at the gearbox end. Tiny (and I mean tiny!) changes here make a big difference. Fine adjustment is by the 2 adjusters on the injection pump belt.

If I remember correctly the bolt on the cam pulley needs to be re-torqued to 160nm. I found it quite hard to get hold the cam still while I undid the bolt as had marked everything up and was concerned I'd loose my marks. Although this can prob be put down to my inexperience with this job.

I remember Artiedke mentioning he had to adjust his settings a number of times then re-read the timing to get it right.

Good luck,
Rich

[Volvostudent]

Hi Galaxie390, thanks for pointing out the adjustment amounts, that's really useful, and thanks also for not leaving me hanging

My mechanic friend is asking me if I've got the instructions to do it yet..I really have trawled through all the info I could find, but am still not really sure of the right way to do it, some of the posts seem to differ in approaches..

If anyone could perhaps post the steps from Vida if it has them I'd be grateful!

Is the correct way to adjust it whilst the engine is running and Vol-fcr, or is it a case of engine off, then adjusting, then running engine to check with Vol-fcr, and then repeat until in range..

Cheers

[artiedtke]

Originally Posted by Volvostudent

Is the correct way to adjust it whilst the engine is running and Vol-fcr, or is it a case of engine off, then adjusting, then running engine to check with Vol-fcr, and then repeat until in range..

Apologies, I seem to have lapsed for a fair few months and missed all this.

After seeing how close the adjuster was to the actual belt, I personally decided to switch the thing off as I value my fingers !!! Maybe with a longer hex key you could do it running.

You seem to have this sorted now so sorry for being late, may be of help to others though if they come across this post.

[Volvostudent]

Cheers artiedtke, yeah got it sorted in the end.

If I recall correctly I ended up doing the 'fine-tuning' adjusting of the timing whilst running with a longer hex key (but yeah, definitely not for the faint-hearted in terms of the belt being very close indeed to the fingers!!), I also had my mate on the laptop letting me know how the adjustments were going in terms of the readings on Vol-FCR.

Well, your timing range of -0.4 to -0.8 degrees after 20k as you mentioned in your other post is testament to the switching-off engine method!

[brickman]

Yup I bottled it and turned it off too.

I was worried that there was some software reason why the engine could not be turned off during adjustment of the timing, but I figured its actually preferred to do it running because if you adjust it too far out of range you won't get it started again!

Mine only took 3 or 4 switch off's and adjustments to get it to -0.3/0.4. I could get it to 0.0 fairly easily however wasn't sure if 0.0 or -0.5 is the target 'sweetspot'

[artiedtke]

Originally Posted by brickman

if you adjust it too far out of range you won't get it started again!

From my own experiences I don't think its even possible to adjust it out that far using the roller.

Originally Posted by Volvostudent

albeit with the occasional connection dropout, perhaps due to weakish battery in car..)

I have had this on various laptops. It turns out that because of the USB <-> RS232 conversion going on in the adapter you need a very very fast laptop to "keep up" with the data transmission.

I was planning on grabbing an actual serial cable (9 pin instead of USB) to see if this would make any difference.

[Volvostudent]

Yeah too much adjustment out means not being able to start the car, this happened on our first efforts, along with much fruitless cranking and plumes of smoke, lol

Although if I recall correctly we were one tooth out in the wrong direction with the belt - as soon as that was sorted the car started fine, and then we did the 'fine-tuning' adjustment to the top of the range (that Vol-FCR showed) at 0 degrees (to me the engine felt smoother there, and I figured that the belt would stretch anyway over time).

I think brickman said in another thread that his set up is stable now with the cable that has the newer FT232RL chip in it, he also mentioned running it in 'XP mode' in Win7, so based on that I wouldn't necessarily think that a serial cable is the only option for a stable connection.

I also found I had to make sure the firewall on the laptop wasn't interfering with Vol-FCR, - still got connection droputs after dealing with that, fortunately there was enough time to get pump timing readouts.

[brickman]

Yup disable win firewall and all WIFI/BT/IR/LAN connections, also pause any virus protection etc for the duration.

Running XP as a virtual machine within Win7 ultimate x64

I never tried the 'BM' chip so couldn't comment on the difference between them, it could be thats what's making the difference or it might be irrelevent!

It does still drop the connection, but after 3-4 minutes, which is more than enough for most things.

[CasualAlien]

Afternoon. I realize that I'm new here, but have lurked in the background, using the site as a good reference, but with this problem I'm really stuck so please help me.

I have been busy with our Volvo V70 TDI (97) getting ready for the MOT this year.
I noticed that it was becoming harder to start & a little smokey! I knew that this could be caused by the pump belt timing over time, so I decided to change it for myself, maybe a big mistake!

My method:
Before new belt:
1/ fired up the car for the conditions for VOL-FCR.
2/ Checked what the timing was at & got a -6 deg reading
3/ Checked the tensioner and it was already adjusted past the marker so no room for adjustment there.
4/ Checked the bottom pulley and that was already at the point where it would only got back on itself.

So simple I thought! just fit a new belt.

1/ set to TDC and marked the other points for reference.
2/ loosened the bolt on the side of the pump to lock it into position.
3/ I slackened the tensioner nut and removed old belt leaving the bottom pulley where it was for reference as mentioned in a previous post.

With new belt:
1/ Started car for conditions to come back again.
2/ Rechecked timing on VOL-FCR and got a -6 deg reading!
3/ Tried to adjust tensioner whilst running but it only got worse up to -9 deg

I thought this would be in the plus due to the new belt. and that I would have to back off the pulley a bit.
I now have a car that if it does start it smokes like a tyre fire
Now I'm not sure what to do.

Would getting a new tensioner do the trick? any suggestions how to get this right again would be great.