My octy started playing up in the snow last week...

Under acceleration in 2nd gear it will get to about 2500 rpm, really hesitate & then struggle up to 3000 when it then feels better. Lots of blue smoke out the back when doing this! Also ASR light came on... Symptoms same with ASR turned off, but it does feel like the ASR cutting in big time!

Looking under the bonnet the clear fuel delivery line looks like it's full of foam there is so much air in there, so I check the Fuel lift pump fuse - OK (Swapped it with the ECU one to prove it!). I pulled the plug off at the pump with the engine running - no change in symptoms & no volts at pump plug...

So does anyone know if there is anything else in 'the way' between the fuse and the pump (EG crash sensor , cutout relay etc) & where it is located so I can hit it one?

Booked into dealer for a check tomorrow but would like to get it sorted...

Thanks

David

Edit: 51 plate 1.9Tdi Elegance

Edited 8 December, 200817 yr by DJM

^&%&^%%(& took it to the dealer.. Explained EXACTLY what the problem was - no power to lift pump. "I'll put it on the tester..." ... Later "Doesn't show anything wrong, 2 temporary faults now cleared"... Grrr Still pipe full of foam (And I mean foam not bubbles!) and no go....

Anyone got a schematic for the Octy (or can point me at where to gt one - other threads suggest the Elsawin stuff is no good for the mk1, is the golf / other VW stuff useful?) - at least that shows me what is connected between the 15A Fuel pump fuse and the 2 wires on the top of the tank.... I'm sure its going to be something trivial & stupid & I don't fancy paying MD rates given their lack of interest....

D

How many wires do you have in total at the plug on top off the delivey unit?

2 .... I assume it is the pump as they are quite thin but I could be barking up the wrong tree here!

Plus I didn't reverse the fusebox layout so am not sure which fuse I checked - but the fuel pump is number 28 and there isn't anything in that one!!!

D

PD's have lift pumps, you have the 1.9tdi. It's lift pump is built into the casing of the VP37 injection pump and is mechanical.

If you have air the first step is to fit a new genuine fuel filter (filling it with diesel from a clean container first) complete with the new sealing o rings for the return line valve.

If that doesn't fix it then you need to fit some clear piping between the line from the tank and the filter, and establish if your leak is further back.

I very much doubt that the lift pump has failed, if it has the metal floating around would normally destroy the pump, also the fact you have bubbles indicates you have air ingress. A failed lift pump will not deliver fuel, but cannot magically deliver lots of air. Air leaks deliver lots of air.

Greg.

As Greg says, but blue smoke makes me think you've got lubricating oil getting into the combustion chambers from someplace too. Diesel smoke is always black or white. (Ok, lube smoke is white too if there's enough of it, but we're talking "making a smoke screen" and litres per mile oil consumption to do that.)

Duh...!

Thanks guys - the question about how many wires made me realise that it was just the level sensor in the delivery unit... I have had the pipes off the filter & can suck through from the tank relatively easily (and couldn't blow back so assume there is a non-return valve in there somewhere!), but couldn't get anything through from the filter outlet pipe (difficult to tell as couldn't get onto it very well) also filter is full if I take the return valve off. Anyway have new filter & return valve to go in tomorrow & we'll see....

Re- Smoke - difficult to assess colour as only happened when on my own, if there is enough vacuum being generated by the mechanical pump might it suck some oil from itself?

Car runs as long as I keep the instant MPG>33 so driving like a granny at present!

D:(

No it won't suck oil through. The smoke is likely due to a) no case pressure meanig the dynamic timing is shot to pieces and also the spray will be due to pumping emulsion of air/diesel. All diesels sucking air that I have seen have ran like a nail and smoked out the building....

There can be other issues, but I'd resolve the air getting into your lines before going any fruther. As the diesel lubricates the rotor head etc, I'd also not drive it till it's done.

Greg.

Edited 12 December, 200817 yr by DGW
Unnecessary use of quote.

New filter and return valve (for good measure) fitted - fuel line is now 'clean' (apart from the 'usual' odd air bubble). Not road tested but feel confident it will be OK!

Peeved as it was serviced (112k) not long ago & they obviously didn't change the filter, although it may not have been on the list!

I have just switched FROM using Biodiesel (B100) (for several years) as my supplier shut down - I wonder if that has had any effect on the filter... & perhaps I should have told the garage to service it as though I was using Bio as they would have changed the filter then....

Ho hum...

D

Well, I would have changed the filter when stopping using biodiesel, even if it wasn't service time.

Biodiesel does two things that have relevence to this thread.

1) it tends to clean 'gunk' out of the fuel tank and system when first used. This then gets lodged in the filter, if the filter isn't changed a few weeks after first using bio you can then be running partially plugged meaning air ingress is more likely to happen due to more suction pre-filter.

2) Bio is made with methanol which attacks seals very badly. Bio is supposed to have all the methanol recovered, such as by spraying it in a vacuum and boiling the methanol off. But unless made very well or by a big plant, it often has some in. This won't show up as fault for a while, till seals start to leak. When you replace the fuel filter, a genuine one comes with new seals to rectify the issue. Bio also attacks rubber fuel lines so look there too if you have further trouble.

As for should the filter have been changed, I'd recomend doubling the frequency if on bio due to the cleaning/waxing issues and to keep the seals fresh.

As for what's done on a service, well there are 'services' and there are Services.

I was looking at a receipt from VW for a 'service' on a medium miles Sharan which has FSH. They listed oil and oil filter as the only parts. Looking round the vehicle, it's clear it has never had the door hinges greased, diesel filter replaced etc.

I have my own terms for what I call a major service but yes agree that the fuel filter on a diesel, pollen, oil & air filters are the basics. I like to flush the oil, not just change it, use an anti-leak additive pack & injector cleaner, grease all the hinges, teflon lube the locks run a VCDS fault scan etc. You can spend a half a day of solid work on a car to do a major service properly. I call other stuff an oil change.... or at best a minor.

Glad you got it fixed,

Greg.

Greg

thanks - I know about Bio - its been on B100 for at least 4 years & 60k so it isn't the 'bio cleaning out the crud' problem... I suspect that switching back to petro diesel might have dropped muck out of the system - I have used it in the interim when I couldn't get bio... It wasn't a planned switch back more 'oh the suppliers shut down'.... AFAIK according to the service schedule the fuel filter should be changed every time if using bio...

Anyway motor much happier now & so am I