BKC PD engine, running out of fuel

[J.R.]

I am down to zero mile remaining on the dash display in my new vehicle and prefer to run out to know just how many miles remain after the zero and how far I can go on a tank, I carry spare fuel.

 

Are there any concerns with running the PD injector system to dry or any special re-start procedures?

 

Thank you.

[gav_is_con]

Think in general it's bad for diesels to run out of fuel, sure someone will be along to confirm. Restarting it may be an issue. 

I managed to get about 30 motorway miles when showing zero. Some start stop slowish miles. 

[wiilydog]

Best to avoid running completely empty as there may be settlement near bottom of the tank that may cause more harm than good to the fuel injectors.

[john999boy]

2 hours ago, J.R. said:

I am down to zero mile remaining on the dash display in my new vehicle and prefer to run out to know just how many miles remain after the zero and how far I can go on a tank, I carry spare fuel.

Just think how many more miles you’d get if you didn’t carry the extra weight of the spare fuel! 

[SuperbTWM]

A PD engine is just about the best engine to run out of diesel on as there is no HPFP to ruin, however there is still the lift pump and the tandem pump to damage. Then you will probably have to fill the filter bowl up with diesel otherwise you will spend a lot of time cranking the engine trying to get it to prime increasing the likelihood of damaging the fuel pumps.

 

To me what you plan to do is a bit stupid

Edited 25 September, 2018 by SuperbTWM

[Guest]

Don't worry about running low on fuel and introducing debris, the fuel is taken from the bottom of the tank where it would be anyway, floating debris that would normally be above the feed would be caught by the filter, that's what it does... filter!

 

I've found that when the filter assembly is bone dry when changing a filter after cleaning the internals, it only takes half a dozen cycles of the ignition from off to on (not start) to prime the system again and have had no issues upon starting.

[J.R.]

Thanks MicMac, thats exactly what I wanted to know!

 

My Mk 1 Octavia ran out loads of times both intentionally and unintentionally, on that I could reduce the battery and starter abuse by opening the bleed screw on the pump or slackening the union on the last injector, I also had the sender unit out several times for repair and finally replacement so know the system well and have absolutely zero worries about debris and dirt problems.

 

If worse comes to worse I can remove the top of the fuel filter bowl and fill it up so I will try 6 primes then cranking for a short while, another 6 primes and cranking and then will prime the bowl if needed.

 

On the MK1 before I knew about the bleeding (I'm a real petrol head but had never had diesel before) the engine cranked for what seemed like 10 minutes (an amazing battery) and the starter was smoking before it started, yet that same starter performed as good as ever afterwards right up to 325000 miles when I scrapped the car.

 

To me its important to know exactly when a vehicle will run out and what to do when it does, also if there are any dangers, I did not think there would be with the PD engine.

[Guest]

Admittedly when changing the fuel filter the system post filter wasn't dry which would probably account for my starting being nothing unusual, bursting into life instantly without any excess cranking.

 

It is important to cycle the ignition several times as I believe the LPFP runs briefly at ignition on just to prime the fuel system, having drained the filter housing completely and not pre filling it, the several cycles seemed prudent.

 

Of course running the system dry may cause a lengthier starting experience however as long as you refrain from cranking until you melt something it'll be fine.  They are designed to work without old-skool manual priming.

[J.R.]

"Bit stupid" here reporting back after finally running out of fuel, boy did it take a long time, 110 miles and over 3 hours of tootling around, I had to return for lunch mid journey .

 

I stopped when I felt the throttle response changing so as not to run the lines and secondary pump dry, from past occasions I know there is still a few miles left beyond that, I have also been reading the VW self study course on the engine and know that the fuel pump will always retain some fuel and self prime.

 

The car restarted after a few priming cycles, its range is 800 miles per tank and now I know that there remain over 100 miles after the fuel computer says "zero miles" if driven carefully.

 

The handbook says tank capacity 55 litres of which 7 litres reserve capacity and now I know exactly how this works, why the range shown after filling up drops off drastically at around the 1/4 tank mark, it slowly removes the 7l reserve capacity from its fuel remaining calculation, when I fill up it shows a range of 800-820 miles which is exactly what I got from the last tankfull after driving 110 miles on "empty".

 

When I put 5 litres into the empty tank and restarted the display showed 40 miles remaining so it saw the fuel and made a reasonably accurate conservative calculation, within 3 miles it had dropped to 20, then 15, 10 and finally zero miles again whereas in fact I had only used about 200 millilitres.

 

So who is the stupid one? The person who deliberately runs out of fuel or he who only ever gets to use 87% of their fuel tank capacity? Over the life of the vehicle thats a lot of extra fuel stops.

 

Hope the info is of use to somebody, if it only stops them doing a half crown-threepenny bit when they think that they are out of fuel because the dash display says so and they are on a motorway 50 miles from a turn off or fuel station my time will have been well spent.

[AVHreplica]

Think generally the low warning for fuel is just simply to generally warn for low level fuel  (not accurately)  and that to provide general protection to the car's systems  (have also seen fuel filters after the tank to be cracked or damaged so not always rely on the filters)  and to prevent entering into possible trouble when for example travelling in unknown places over mountains where not sure how close is the next fuel station and etc..etc...etc..

So, the only sure is that manufacturer does not provide accuracy and what you can do with the few littres remained in the tank , besides the remaineing driving you can have with that end part of the tank depends on so many other factors..

It's just informative...

It depends on each driver how wants to proceed when entring in the red zone...

In previous experience from other cars i knew the red level could maintain 50-70 kms but other times with that same car it got me only 20 kms  (heavy rain with full working wipers, AC for defrosting, high beam and and fogs....that time the fuel was killed right away..)

[seriesdriver]

21 hours ago, J.R. said:

 

 

So who is the stupid one? The person who deliberately runs out of fuel or he who only ever gets to use 87% of their fuel tank capacity? Over the life of the vehicle thats a lot of extra fuel stops.

 

 

 

On reflection its the 1st one, yes very much the 1st one.

[SuperbTWM]

 

Why don't you see how low you can get the oil level so we can all save money on oil changes, that would be a better money saver.

 

[Breezy_Pete]

@J.R. Good work.

@MicMac, helpful input to the experiment

Weird how much negativity there is about.

[Guest]

I can't get my head around many sheeple's brain logic who top up every time they pass a filling station.

 

Realistically we are never far from a 24/7 filling station and most cars will do more than the distance to one should the low fuel warning trigger.

 

Yet they continually top up like fuel was going to run out, seemingly oblivious to the extra weight/cost penalty of carrying a full tank all the time, not to mention the time in their lives wasted with each visit to the filling station.

 

If your car has a range of hundreds of miles with a full tank why top up every 50...

 

I suppose it's to be expected in this day and age where common sense is a rare thing.

 

I wish more folks had an idea of how the world worked in practical terms and relied less on technology to do the thinking for them.

 

I'd better stop there or else I'll rant on and on.

 

Have a nice day y'all.

[gav_is_con]

@J.R. amazed how far you traveled on empty. I still wouldn't have the guts to to it that much. As others have said there are factors that affect what distance you would actually get. 

I have noticed a 55 litre tank can take more fuel on those occasions than 55 litres. I would be interested to know if you refuelled full tank how much you put in and any brim to brim analysis of MPG. 

[J.R.]

19 minutes ago, gav_is_con said:

@J.R. amazed how far you traveled on empty. I still wouldn't have the guts to to it that much. As others have said there are factors that affect what distance you would actually get. 

I have noticed a 55 litre tank can take more fuel on those occasions than 55 litres. I would be interested to know if you refuelled full tank how much you put in and any brim to brim analysis of MPG. 

I put in 5 litres from a can, might not have been completely brimmed in case of expansion leaks, drove to filling station probably consuming 200ml, then filled up the can again and the tank very slowly till the fuel was just beneath the top of the filler neck and would not go down any more, it took 54.5 litres so I reckon there was 0.5l remaining in the tank which might have been sucked up with a lot of air if I had continued even further.

 

I had not brimmed completely in the UK, people get cross in Tescos so I actually got 780 miles from the tank, the 820 was calculated from my average fuel consumption, the computer will get checked on my next fill up which will be a slow one again, on my old MK1 you the difference between a quick fill and a painfully slow one was at least 5 litres, not sure if the tank is a better design on the MK2, also fuel here in France is very foamy.

[J.R.]

49 minutes ago, Wino said:

@J.R. Good work.

@MicMac, helpful input to the experiment

Weird how much negativity there is about.

 

It must be a change of demographic between MK1 and MK2 owners, was on the MK1 forum for 12+ years and never experienced the slightest disagreement, of course I have had an extra 12 years to perfect my idiocracy

[AVHreplica]

3 hours ago, MicMac said:

I can't get my head around many sheeple's brain logic who top up every time they pass a filling station.

 

Realistically we are never far from a 24/7 filling station and most cars will do more than the distance to one should the low fuel warning trigger.

 

Yet they continually top up like fuel was going to run out, seemingly oblivious to the extra weight/cost penalty of carrying a full tank all the time, not to mention the time in their lives wasted with each visit to the filling station.

 

If your car has a range of hundreds of miles with a full tank why top up every 50...

It has to do with psychology..!

There are many who are pleased or feel good or feel better or feel safety to continusly keep on seeing the gauge on the top  (..or almost..).

Not sure why exactly they should think and act that way but it can be explained somehow..

Edited 27 September, 2018 by AkisVH

[J.R.]

Everyone is different, we should accept and embrace that rather than feeling intimidated by it, we can all learn  from people who go about things differently than how we would, more than we would from clones of ourselves no matter how comfortable they might make us feel.

 

 

[AVHreplica]

1 minute ago, J.R. said:

Everyone is different, we should accept and embrace that rather than feeling intimidated by it, we can all learn  from people who go about things differently than how we would, more than we would from clones of ourselves no matter how comfortable they might make us feel.

 

..... ..... yeah..somehow like that.....i'll agree.

[09facelift]

On 27/09/2018 at 15:54, MicMac said:

 

 

Realistically we are never far from a 24/7 filling station and most cars will do more than the distance to one should the low fuel warning trigger.

 

You  should try driving around Ireland....you'd be surprised how far you can be from a 24/7 filling station 

[Guest]

@09facelift

 

I thought you guys were still using horse and cart over there, grass by the roadside is free!

[09facelift]

6 hours ago, MicMac said:

@09facelift

 

I thought you guys were still using horse and cart over there, grass by the roadside is free!

 

No, we've electricity and running water these days, believe it or not!

[Guest]

@09facelift

 

Typically the two don't mix!