Hi all,

I have a 2004 (new shape) Octavia TDI 1.9 pd. The car is fantastic, drives well, picks up well, is quiet and very cheap to run. BUT acquired two fairly serious problems.

First problem is when the car is really cold it seems to miss-fire when starting it. This will only last about 3 minutes until there is some heat there and quite often will lose revs and cut the engine out. The car starts ok when cold but a few seconds into running it will momentarily cut out. When I say miss-fire I am not sure that is what is actually happening, after all there is no BANG, coughing or excessive smoke. The engine sounds like it is running fine apart from this issue.

The second problem is re-starting the car when it is at temperature. It will always start however takes 4-5 seconds to fire up and again no coughing or smoke. The engine turns over fine and does not sound like it is turning over any slower. I have read a lot about this problem online and I am considering changing the engine temp sensor but not sure where it is located.

Thanks for reading and all advice would be appreciated.

either egr or tandem fuel pump mate

Hi

I ain't a mechanic - so don't quote me However, I do remember reading a thread here about problem number two. if you search for battery or hot starting you might turn it up.

Apparently, when hot, by design the car doesn't supply fuel until the engine is spinning fast enough. If it doesn't spin fast enough the car will crank for 30 seconds and then inject fuel to start anyway.

The fault is simply an old battery that can't crank the engine fast enough.

As for your first fault, I suggest you get the DTC codes read to see if you car is logging any faults, for example, defective glow plugs.

HTH

Hi

I ain't a mechanic - so don't quote me However, I do remember reading a thread here about problem number two. if you search for battery or hot starting you might turn it up.

Apparently, when hot, by design the car doesn't supply fuel until the engine is spinning fast enough. If it doesn't spin fast enough the car will crank for 30 seconds and then inject fuel to start anyway.

The fault is simply an old battery that can't crank the engine fast enough.

As for your first fault, I suggest you get the DTC codes read to see if you car is logging any faults, for example, defective glow plugs.

HTH

Thanks for the thoughts, there is a brand new battery on there and the starter is spinning just as fast as when it is cold.

My biggest worry is the fist problem. I have now read the fault codes and the only one that stays is the Air Intake Temp sensor. I would love to change that and see what happens but i cant find it.

Any ideas where it si on the 1.9 pd engine.

Thanks again

Google is your friend

Apparently it is built into the MAF - according to vwaudiforum

HTH

Google is your friend

Apparently it is built into the MAF - according to vwaudiforum

HTH

Im not sure this is the case on mine.... i tried the MAF by unplugging it and running vagcom, the only fault code i got was MAF low signal it was only later on the Air Intake sensor came back on. They seem to have different fault codes :S

If all else fails pop down & see Jabba as they are local to you http://www.jabbasport.com/about_us.php

They have done work on 3 of our diesels as well as a petrol Octy & the Abarth, Always excelent, cheaper than the main dealers & definately a lot more knowledgable & I travel from hampshire to use them

Edited 30 November, 201015 yr by Stuart_J

The hot starting problem is usually the starter. It might sound ok but not spinning it fast enough for the ECU.

The hot starting problem is usually the starter. It might sound ok but not spinning it fast enough for the ECU.

Yeh i have only heard good things about jabba sport, once i have sorted this mess out i may ask them to re-map it.

I dont want to spend too much money on it until i know its going to be ok.... Would love some help with the air intake sensor and its location :S

thanks again