Few questions

[Lou306hdi]

OK so this is my first hdi, it's got a few niggles, one that's doing my nut in is if it's below 10° it takes forever to start, I'm assuming glow plugs of some sort?

Also what's 'normal' for boost? Like when does it start in the Rev range ect.

Ooo and it's meant to be for work but that never lasts... so what are the tuning steps? I had a xudt years ago and that was mess with the pump and mess with the waste gate(I think) and voila, more of everything... apparently I have to map these engines? Do I need to do anything before that? Or is it simply buy from one of the many websites (hdi tuning seems to pop up on posts alot) and buy one of those cables and pop it on to my ecu (where ever that is)?


Sorry for the possible nooby questions. Haven't quite mastered tapatalk app yet :S

[Poodle]

Hard to start below 10 degrees is unlikely to be glow plugs, these don't suffer much without them. Might be worth having a look at the fuel filter and fuel pressure regulator, there's more info in my sig.

[Toms306]

Possibly a temp sensor fault for the starting issue. I assume you've checked the battery is good?

As for stage 1, yes it's a remap and you don't need any other mods, just buy a map and flash that to the ECU. You do that via the OBD port under the dash, rather than directly to the ECU on these.

[Lou306hdi]

@poodle I can't see sigs on tapatalk :'( , battery seems good, someone mentioned something about leak off pipe? I'm confused

[Poodle]

Oh, well that's crap, glad i don't use it lol. It's all in the guide section, have a browse.

Temp sensor is a gpod shout as well, i seem to remember there are seperate feeds to the dials and ecu, could be wrong though. You could do a leak off test on the injectors, see if they're leaking back too much fuel which would make it hard to build pressure on start up.

Normal boost threshold is around 1900rpm for these, sorry missed that question before.

[Lou306hdi]

OK another question, should my car have this?
My mechanic says it shouldn't :'s
Changed the leak off pipes today, seems to have helped slightly

[Poodle]

It should, that's a fuel line damper, perfectly normal. Tbh it sounds like you need a new mechanic, changing the leak off pipes was never going to help a starting problem lol.

[Lou306hdi]

Oh :/ well there changed now haha going to do a service when I get paid, apparently the guy I got it from serviced it last month... but no proof :/

[Poodle]

Hmmm, i'd watch that mechanic carefully in future bud. Have a look at the oil on the dipstick, if it's not jet black it will have been done recently.

[DeeTurbo]

Just thought I'd mention my estate had a similar issue in the winter it would have to turn over loads before it would start. I checked on some diag hardware and it was showing the fuel system wasn't getting up to pressure.

I changed a few things and it turned out to be the injectors. I did a leak off test and that didn't show any fault strangely, they were all leaking off the same amount.

I you only getting the starting issue on the first start of the day or is it ever time you try starting it?

[Poodle]

Just because they all leaked off the same amount doesn't mean they were ok, there is an upper limit for flow. Can't remember what the figures are exactly, but it's something like 8ml a minute, which really isn't a lot, need to perform the test over half an hour to get useful results.

[Lou306hdi]

@deeTurbo @poodle I think something to do with fuel pressure may be the problem, the time to start is significantly reduced the more diesel I have in the tank, also the oil is black so I'm guessing no service?

On an unrelated note, if I put the back seats down I can lie in the boot.... happy days

[Poodle]

Ahah ok. Pull out your lift pump and have a look at the strainer and the bottom of the tank, there may be some muck blocking it up a bit. Alternatively, do you run the fuel right down through the red or park on a slope at all?

[Lou306hdi]

@poodle iv generally waited till the light came on then filled up.... that bad?

[Poodle]

No that shouldn't be a problem, just trying to make sure we don't miss an easy solution. Have a look at the lift pump assembly, if it's clean and altogether then chances are you'll be wanting a new one.

Definitely check the condition of your fuel filter before buying anything though.

[Lou306hdi]

@poodle what should it look like? I been in a petrol for the past 3 years soo yeah ....

[pug306driver]

The tank lift pump removal and cleaning is quite easy and straight forward, I did it about 3 weeks ago.....but read/look at the guide in the guide section several times to make sure you know the procedure, take your time and always prey out loud when doing anything with the plastic bits, "please god don't let me break these bits !"

I didn't figure out how to remove the fine filter screen on the bottom of the pick up but an aerosol spray cleaned it ok, with a very similar amount of that black stuff as in the guide.

Be very careful fitting the unit "ring" as it seems easy to cross thread, as someone has proved.

See the guide on the fuel filter as well, use a pug filter as pattern ones seem slightly larger and don't fit that well, ending up tight in the filter housing and crushed.

When the lift pump is out of the tank, you will see the float and "tank shelf".....the pump unit is not "keyed" so be careful that the float does not sit on the "shelf" inside the tank, if it does the gauge will show fuel in the tank when its run dry.

I have only run the tank low on fuel once to check the low fuel warning light worked, but I now top up then tank at or just below 1/4 full.

Follow the Haynes manual about bleeding, or purging the fuel lines from tank to filter.......ours has that round metal "damper" unit just like yours.....

post pics of the lift pump filter and fuel filter.

I found that using a good fit ring spanner on the fuel filter "hex head" helped, I push down quite hard on the ring and turned slowly, it came off all ok, and was easier to put back on this way. Perhaps a hex socket or spanner would be better.

As suggested, look for "yellow metal flakes" at the bottom of the filter housing, suggesting a worn lift pump.

[DeeTurbo]

Just thought could it be the "brown relay", when you turn the key on the second click do you always hear the pump prime?

I've had it in the past where it's not primed/run the pump and when tying to start its not starting because the lift pump hasn't started to run and when it does run it starts.

[Magenta Sunset]

-or use a strap-wrench around the filter housing top

[Poodle]

The fuel filter should look like a relatively clean paper filter element, try google if you don't know what that looks like. If it's tending towards dark brown/black or looks crushed you need a new one, genuine is best although high quality oem spec replacement is fine. Important note: halfords does not count as high quality, much the reverse lol.

The famous metal flakes are unrelated to lift pump wear, they appear regularly in cars without lift pumps. These systems are self-bleeding, don't go loosening high pressure pipes or anything, just cycle the ignition on a few times for a few seconds at a time. There is an arrow on top of the pump which matches one on the tank to avoid misaligning the pump and getting the fuel level reading issue.

If you have a 6-point socket that you can use on the filter housing do so, that or if you only have a 12-point use something else to grip the outside edge of the lid for extra turning force to minimise the chance of mullering the hex head. Steady and measured application of force is your best bet, the usual bouncing method to free off stuck fixings just makes it more likely to round the head in this case.

[pug306driver]

I saw the arrows on top of the lift pump but didn't see the arrow or mark on the tank top, but will check.

Yellow metal flakes or glitter in the filter housing, didn't someone say that's due to possible worn lift pump?

[Poodle]

It was thought of as common knowledge tbf, but now i've seen it a lot in cars with no lift pump so it's back to the drawing board with that as far as i'm concerned.

[pug306driver]

Maybe the yellow glitter I found in the filter housing is from the yellowish wavy spring washer at the top of the filter housing, it did seem to have some worn patches with a steel looking metal under the plating?

[Lou306hdi]

I took my pump out... carefully, was a load of what looked like black sand in it... not sure why, cleaned it gently, and voila starting problems sorted (y) thanks @poodle and who ever else there was thank you all .. on to my next problem... my passenger window doesn't work :'( going to check the wires in the door loom tonight or tomorrow

[Poodle]

Glad you fixed the issue, although that black sand could well be the lift pump starting to break up. Meh, if it starts happening again at least you will know where to start looking. 

I don't think those flakes come from that ring either, since it doesn't feature on other engines with the issue. I suspect it's from the injectors or pump, but i've got no evidence and it's not really important so i never bothered looking into it properly.

I just took this from a new scirrocco earlier today (no lift pump), in case anyone wanted picture evidence:

....hmm well i did, but it seems reluctant to upload over 3g, maybe later.

[dimar]

Regarding the metal flakes, apparently they are coming from the petrol stations pump gear and have nothing to do with the car's pumps.

[Poodle]

Ahah interesting to know, thanks.

[Lou306hdi]

@poodle don't suppose you know what turbo I have? The cars done 180k, as I'm using it everyday I'm planning on getting a rebuild kit, servicing the turbo if you like just to make sure it's good for another 100k! [FACE WITH TEARS OF JOY] is it the usually kkk/k03 or is it like the xud that came with one of two (presumably whatever pug techs could reach)?

[Poodle]

It'll be a k03 or a garrett gt15, can only tell by looking yourself tbh. One has a thumb wheel as a wastegate adjuster, the other has nuts. I can never remember which way round it is and my box of turbos is properly buried in the garage, will have a dig tomorrow if i remember.

[Lou306hdi]

Haha that's OK I'll have a proper look on Monday