Before you replace the tandem pump, are there any slight diesel weeps from the connecting hose(s)?

If there are that's where the air will be gaining access, whip the clip off and replace it with a suitably sized hose clip (jubilee etc).

Preferably replacing the section of hose as it may well have hardened and be impossible to properly clamp given the small size of the clips.

Wishing you luck and a refund on your new pump which could be spent elsewhere.

can anyone point me in the direction of the tandem pump? picture maybe? so I can check these hoses etc too...

can anyone point me in the direction of the tandem pump? picture maybe? so I can check these hoses etc too...

Number 9  End of camshaft.

 

Edited 10 February, 201511 yr by IngusSeflers

If you go back a few posts there is a link to euro car parrts with a photo of the pump,these faults need to be properly diagnosed rather than everyone making wild guesses.

I always find the worhshop manual the best place to start, and then having the right diagnostic tools and equipment to carry out the necessary tasks. But not everyone is comfortable to undertake this kind of work.

I always find the worhshop manual the best place to start, and then having the right diagnostic tools and equipment to carry out the necessary tasks. But not everyone is comfortable to undertake this kind of work.

That little bit confuse me...

How mechanic can run the Business/garage without skills and equipment to test simple fuel pressure?

Avoid that kind of mechanics lads, they are Car Butchers    

That little bit confuse me...

How mechanic can run the Business/garage without skills and equipment to test simple fuel pressure?

Avoid that kind of mechanics lads, they are Car Butchers 

Which little bit confuses you

Which little bit confuses you

Mechanics without skills and equipment in garage...shouting 'Pump is dead' without any investigation  

That confuses me...

Trust me their are a lot of garages in the UK that are like that.

Appreciate all the info guys... one quick question, is it possible to get these values from anywhere inside VCDS? im not going on  a wild replacement regime it was more to check the hoses etc going to it as mentioned in the post above somewhere

Appreciate all the info guys... one quick question, is it possible to get these values from anywhere inside VCDS? im not going on  a wild replacement regime it was more to check the hoses etc going to it as mentioned in the post above somewhere

Pump pressures on pd engines cant be found in vcds,see above post from Ingus with drawing and details of pump pressure test.

Also check around the fuel filter for any leaks, if you open the bonnet with a hot engine and get the merest whiff of diesel you've a leak somewhere, follow your nose.

The increasing numbers of these threads are concerning.

Been there got the t-shirt. I'm afraid my car had several more thousands of pounds spent on it, even Skoda Technical Support in the Czech Republic couldn't sort it.

The issue is likely related to the VOSA injector recall which applies to all VAG PD170 engines. Far too many botched injector changes at Skoda main dealers. Skoda UK know but don't really care.

See here for further links to the many, many other people who also suffer from this. I've yet to find one who's managed to get to the bottom of it.http://www.briskoda.net/forums/index.php?/topic/338651-Cold-start

Good luck!

Sounds like no fuel initially and then starts when it draws fuel through. Maybe worth fitting a non-return valve in the low pressure side to see if it stops fuel running back to the tank. A valve will only be a few pounds and may help to narrow the problem down.

I'm active on another Vag forum and its long been known faulty coolant temperature sensors cause cold start problems on the tdi engines. On many versions, they are actually dual devices, one side feeds the temperature gauge, the other feeds the ecu and influences mapping. IIRC if you disconnect the sensor, the ecu adopts a default value and often the engine will start instead of struggling - i may be wrong though.

If you havent already, I'd recommend you change it, they are cheap enough.

Edited 10 February, 201511 yr by xman

 I'd recommend you change it, they are cheap enough.

Another recommendation to spend some money without any obvious reason  :clap:

Did anybody saw that sensor in Live data or tested with multimeter?  :peek:  Maybe that sensor is 100% in order and changing good-one OEM sensor with some new-one CHEAP-one,can switch off the light in the end of the tunnel! 

To help you understand made some screenshot. All Greens effect Blues.

 

I suggested it because the op already stated that the sensor is faulty. Its showing 15 deg low, I assume on the gauge side. The ecu side may be way out.

Ive not seen any mention of vcds or official skoda/vag scan. Often, but not always, vcds can pick up if this sensor is faulty.

Edited 10 February, 201511 yr by xman

I suggested it because the op already stated that the sensor is faulty. Its showing 15 deg low, 

Sorry, I missed that fact...  :peek:

BTW, is that temperature sensor replaced? 

Guys, I noticed there are 2 temp sensors, G82 and G83.. which one is usually the offending one? Im going to get a vcds scan done by my mate, is there anywhere else I should be checking for common values?

The two sensors are combined into one unit.

The two sensors are combined into one unit.

 

Not sure about that.

 

I have two physical sensors on my old 1.9tdi engine, one on the radiator hose (equivalent to G83 in the diagram above) and is a (dual I think) thermoswitch used to control the fans. The other is close to engine block and measures the coolant temperature for the guage and the ecu (this is dual device using NTC themistors).

 

Consult Ekta for the definitive answer.

^^^  :yes:

My friend on his.fabia 1.4tdi had similar issue. The injector o-ring were changed as pressure was escaping. He noticed this more from half tank down, with time it got worse as more time left without running,

The fuel filter was changed as with time oil appeared inside filter as fuel returned. Each oring kit costed less than 20€. This issue was resolved at a Bosch car service and they informed my friend that the oil inside engine wasn't adequate for that type of engine, luckily no harness damage (he bought the car used)

Edited 14 February, 201511 yr by alberg

New tandem pump fitted and no change, still difficulties starting.

Re cap -

Battery

Injectors

Glow plugs

Tandem pump

Fuel filter drained

Various diagnostics

I really am getting frustated now and I've spoke to various garages including the one that has done my previous work who also are lost at where to look now.

As stated before my coolant sensor was reading 15c lower than temp - that's read from diagnostics as the gauge inside the car works fine.

Would that really be enough to cause my problem?

Is this the replacement?

http://www.eurocarparts.com/mobile/ecp/c/Skoda_Octavia_2.0_2007/p/car-parts/engine-parts/fuel-and-engine-management/engine-management-sensor/?223440210&1&792376225bb9dec48baf7de2c820edc2345bcf88&000572

That looks as if its the radiator fan switch ( for CEGA engine which is the 170 CR diesel) Not the temperature sensor in question.

Search here using your car details for the exact part details.

www.partscats.info

Then look the part no up in ebay or google for suppliers. Note that Gsf, euro car parts and even some skoda dealers are on ebay....

You need the engine year and code eg BMN... Also you need to check what colour the sensor fitted is, as there are different colours denoting diffent calibration ranges.

Alternatively you can phone your local skoda parts dept. and ask them for that info and a price to compare.

Edited 14 February, 201511 yr by xman

New tandem pump fitted and no change, still difficulties starting.

Re cap -

Battery

Injectors

Glow plugs

Tandem pump

Fuel filter drained

Various diagnostics

I really am getting frustated now and I've spoke to various garages including the one that has done my previous work who also are lost at where to look now.

i cant see any mention of a compression test having been carried out,

Edited 14 February, 201511 yr by freelanderman