Here's a resistance v temp chart to give you an idea if it's faulty

^  and just because the sender is correct...is the reading making it all the way to the ecu ?

 

can most likley check it with vcds , i use it on my 3f engine and can check what temps the ecu is seeing in real time 

If you can't get live data from a code reader, you could do the resistance check at the ECU plug between pins 8 & 10

id be looking at the plugs regularly now....if theyre in anyway black /sooty then thats an issue 

Thanks guys - I'll have a look with my multimeter and try and get the code reader software I have to work, see what springs up.

https://www.ebay.co.uk/itm/Fits-VaG-GROUP-AUDI-USB-OBD2-KKL-409-1-Diagnostic-lead-2x2-Works-VCDS-Lite-V1-2/153126515006?hash=item23a70d313e:g:IlAAAOSwQc5bZciR:rk:1:pf:1&frcectupt=true

 

something like that and a laptop should read the live data

12 hours ago, steveo3002 said:

https://www.ebay.co.uk/itm/Fits-VaG-GROUP-AUDI-USB-OBD2-KKL-409-1-Diagnostic-lead-2x2-Works-VCDS-Lite-V1-2/153126515006?hash=item23a70d313e:g:IlAAAOSwQc5bZciR:rk:1:pf:1&frcectupt=true

 

something like that and a laptop should read the live data

 

Cheers man - I actually bought this exact kit a while back - had trouble with the software installing correctly, will have another crack at it at some point.

is it a definite single cly misfire or could it be a chug chug too rich mixture kinda thing?

 

never had a spi so not sure...but is it possible the injector could leak overnight and leave a small amount of fuel to upset things on a cold start?

Edited 25 January, 20197 yr by steveo3002

Hmmm... well its definitely a 'chug chug chug', turns into an uneven spluttering when you rev.

yeah ?   are you familar with older manual choke cars and when its too rich?   might be onto something 

 

what if when its chugging you give it a sharp rev , does it improve /clear ?

 

does the tailpipe smell badly of fuel...its gonna smell but shouldnt be like neat petrol

 

keep an eye on plug colour

I'm familiar in their operation but the only car I've owned with a manual choke was a Trabant so not exactly comparing apples with apples!

 

When I next start it up and it plays up I'll try a sharp rev - can't think that I have done yet, normally just around 2000 while getting out of my parking spot.

 

Tailpipe definitely smells a bit - I wouldn't describe it as neat petrol but it definitely 'smells'.

High hydrocarbons is a sign of early gasket failure

10 hours ago, kiran_182 said:

High hydrocarbons is a sign of early gasket failure

 

Which gasket? Just replaced both the head and inlet. It failed on HC in october but then passed when it was tested again hot (and not marginally either - got a decently low reading)

On 25/01/2019 at 15:43, steveo3002 said:

yeah ?   are you familar with older manual choke cars and when its too rich?   might be onto something 

 

what if when its chugging you give it a sharp rev , does it improve /clear ?

 

does the tailpipe smell badly of fuel...its gonna smell but shouldnt be like neat petrol

 

keep an eye on plug colour

 

Right....

 

So I managed to get VCDS to install and run, got it talking to the USB driver and it seemed to talk happily to an address on the car's ECU. Does anyone have any experience with VCDS lite and Mk2fs? Could do with setting up a custom settings file - the included settings for reading a Polo 6N (closest i could find) didn't work too great.

 

However...

 

 

We have a temperature sensor fault! Sounds like the theory of the temp sensor resistance not quite making it to the ECU pins unaltered. The resistance across the sender pins is in the right range for the temperature so its likely a short on the way to the ECU.

 

So the running theory is the engine thinks its cold all the time while warming up, potentially all the time period. This would definitely explain the fouled plugs, the fartiness when cold and the fact that new plugs cures the problem for a few drives.

 

I think we're getting somewhere!

Just went out with a multimeter - there is a good connection on the +ve wire from the sender to the ECU but the ground wire (brown + white) doesn't have a good connection to any common earths I could find in range of my multimeter probe.

 

Its all come down to a wire. One sodding wire!

please repair it with the proper pins 

The earth side is commoned up with the Inlet air temp sensor and throttle position sensor and goes back to the ECU pin 8

surprised it would hot start if broken wire

1 hour ago, nige8021 said:

The earth side is commoned up with the Inlet air temp sensor and throttle position sensor and goes back to the ECU pin 8

 

That is interesting - you would expect that a dodgy earth would effect the other two sensors? I tested continuity between the temp sender earth on its plug and every pin on the ecu plug (so must have passed through pin 8) and didn't get the meter to beep. 

 

I'll have to undo the loom tape and have a good look - at least the cabling is pretty direct eh.

 

59 minutes ago, steveo3002 said:

surprised it would hot start if broken wire

I agree - It also runs pretty efficiently on a long run so i'd be surprised if its totally lost its connection - the ecu would effectively think it was cold all the time and never get to the closed circuit fuelling schedule right? Maybe its just a slightly crappy earth which is bumping the resistance up? 

 

I mean what else could that fault code mean?

oh yeah ..id missed the fault code post 

 

pretty sure you could fit a short wire in its place and earth it direct somewhere  to test  it ?

 

have you cleared the code and had it re appear?  might be an old one

 

dont know why yours says 6n...mine worked out of the box 

2 minutes ago, steveo3002 said:

oh yeah ..id missed the fault code post 

 

pretty sure you could fit a short wire in its place and earth it direct somewhere  to test  it ?

 

have you cleared the code and had it re appear?  might be an old one

 

dont know why yours says 6n...mine worked out of the box 

 

Yeah i'll try a temporary earth tomorrow for sure, also clear the codes.

 

To be fair I hadn't quite figured the software out when I took that photo - was running in '6n' mode but know how to cycle through individual modules now.

get it on the measuring block setting...just use the top bar and view one block at a time , even though it has the facilty to open block 1,2,3,4 at the same time i dont think the polo ecu is man enough to do it and the responce is too slow ...so view one at a time for decent results

2 hours ago, steveo3002 said:

get it on the measuring block setting...just use the top bar and view one block at a time , even though it has the facilty to open block 1,2,3,4 at the same time i dont think the polo ecu is man enough to do it and the responce is too slow ...so view one at a time for decent results

Great tip, thanks! I'll give that a go first and see if the same code pops up before trying a new earth to the temp sender 

On 24/01/2019 at 14:22, steveo3002 said:

 

can most likley check it with vcds , i use it on my 3f engine and can check what temps the ecu is seeing in real time 

 

Out of interest - how do you do that? Is that using a fully paid-up version of VCDS or can you do it with VCDS lite?

heres a poor video of mine 

 

 

from memory connect it up..select engine , and then theres option for block or measuring block? im not near the car at the moment, and no not paid version 

Edited 27 January, 20197 yr by steveo3002