SOmetimes when my W-reg Octy 110 tdi takes a lot of cranking over to get it started when it is hot. No problem with cold starts. i have checked the EGR, and shut off butterfly and they are all OK.

Also there is some extra black smoke when accelerating hard.... Is the pump on teh way out or does it need some adjustment? Is there a temperature sensor that impacts starting when the engine is hot?

VAG-COM did not show any faults ...

Mine used to have the sticking anti-shudder valve, but I think that is the same as the shutt-off butterfly.

I believe there is a temperature sensor which can fail (part of the injector unit?), but not sure of the specifics of it.

IIRc there is a fuel temp sensor which is part of the fuel injection pump.

A derv injection (bosch) specialist should be able to sort you out for a lot less than a new injector.

Could be the coolant temp sensor, they seem to cause a variety of problems, mainly when warm. I think they only show an error when they give a really silly reading rather than just a bit warm so it can be a bit random at throwing errors

Does it idle OK, mine used to idle fast when warm sometimes but then drop back to normal after 30 seconds or so.

Found a link on another forum showing the Fuel Temp Sender (inside) the Injection Pump.

Not sure if I can trace down the wiring to test the sender without opening the pump.

Would this cause teh black smoke on acceleration?

Thanks for the help

The engine starts fine. idles normally....not revving hot or cold....but requires a lot of cranking when hot to re-start. I thought it was the NRV on the fuel filter allowing the system to drain...but this was checked & replaced but no change.

Where is teh 4-wire temp sender unit ...or does anyone know which item to check on VAG-COM to verify correct operation of the tem sender or the injection pump fuel sender. Thanks

Found a link on another forum showing the Fuel Temp Sender (inside) the Injection Pump.

Not sure if I can trace down the wiring to test the sender without opening the pump.

Would this cause teh black smoke on acceleration?

Thanks for the help

Well getting the temp wrong can cause overfueling.

A derv injection specialist will be able to sort it for you and IIRC it was well under 100 notes for them to do the job.

Eddies,

Did you get this solved? I'm having the same problem as well, searching the forums common causes include starter motor and fuel temp sensor.

cheers

David

Hi, I also have this problem with my recently purchased 2001 Octy Estate 1.9 TDi (110). has anyoneone found the definite cause yet ? I think the fuel temp may be a clue as it happened to me after driving for 30 miles on a motoroway so the engine would have been hot, but the air temp was just above freezing. After stopping and filling up with a tank of diesel the car took several seconds to start. I assume that the fuel temp in the injector pump must have risen quickly due to heat soak from near freezing to around 80-90 degC. (diesel engines continually circulate fuel excess fuel from the pump to the tank I believe). perhaps the computer cannot handle a sudden change like this and gets confused ?

Any thoughts on this ?

Julian.

Hi, I also have this problem with my recently purchased 2001 Octy Estate 1.9 TDi (110). has anyoneone found the definite cause yet ? I think the fuel temp may be a clue as it happened to me after driving for 30 miles on a motoroway so the engine would have been hot, but the air temp was just above freezing. After stopping and filling up with a tank of diesel the car took several seconds to start. I assume that the fuel temp in the injector pump must have risen quickly due to heat soak from near freezing to around 80-90 degC. (diesel engines continually circulate fuel excess fuel from the pump to the tank I believe). perhaps the computer cannot handle a sudden change like this and gets confused ?

Any thoughts on this ?

Julian.

For me this was a sticky anti-shudder valve - used to happen during the summer and winter for me, as mentioned in my first post.

Edited 13 February, 200917 yr by mbames

Happens all year round for me, but if its reluctant to start whilst hot.....give it a couple of turns, stop and then turn the key again. Mine usually fires straight up after that.

See how they start from hot with the temperature sensor disconnected.

Not entirely sure where it is on a Octavia 105PD.

No difference with temp sensor disconnected. Mileage does not appear to be as good as it should be so I suspect the injection pump may be faulty / worn.....so I may have to take it to a diesel pump expert.

Try this. The case pressure relief valve on the pump could look like the middle picture. It should look like the one on the right......

Injection pump case pressure - TDIClub Forums

Removed starter motore, and greased the gearbox between the motor body and starter pinion. Car starts without problems as the cranking RPM must be high enough (supposed to be 260 RPM) to allow injection to commence.