Bigt's Big MK 2 project temperature problems.

[OEM G60]

BTS won't bypass the coil by the way

[bigt]

so if BTS wont bypass the coil how can the coil be at fault?
its only when I plug in the BTS that the car cuts out. Ignition timing is perfect(6degBTDC) relays, ecu, sensors, all new.

Reset done and tuned....

[OEM G60]

Yeah that's a weird one, is it a genuine VAG BTS? Might be worth trying another, they do seem to be temperamental little things.

Vacuum lines to ECU could be another thing to check....

[rutti]

Try checking the o2 sensor if you have one, mine did the same thing whenever its warmed up. Did everything as suggested and finally replaced the o2 sensor (you can buy 3rd party from local aussie ebay seller for about $40) and ran flawlessly ever since. My thinking is when the engine is cold, its not relying on the o2 sensor to adjust fueling, therefore it runs fine up until the engine warms up (blue sensor). Faulty o2 sensor kicks in and causing fueling to be all over the place (mine was over fueling).

[ryana89]

If only MK2's had OBD1/2.....

Also, you've all probably seen it, but I find this chart helpful when diagnosing.



Digi2 in/outputs

[bigt]

Hey,

Thanks for the graph but all of that has been fixed.

o2(lambda) has been changed, also the temp sensor has been replaced(twice), EcU replaced, hall sender and knock sensor are functioning too. But worth another look. Otherwise off to the autoelec...

[bigt]

also ECU relay on the graph would be great as well although I have replaced that...

[bigt]

Hi thanks for the graph,

I have done all the above and in regards to the lambda(o2) sensor I used one out of a ford V8 and trimmed the fittings(its the same 3 wires 2 black 1 white).

Worth another check though. I have simply checked all the above for continuity which the show on a multimeter...

My next question is what range should I be looking for on the above? My blue temp sender has 5 ohm resistance, same in the wires regardless of which sensor is in....


Cheers

[MK2GUY]

Try checking the o2 sensor if you have one, mine did the same thing whenever its warmed up. Did everything as suggested and finally replaced the o2 sensor (you can buy 3rd party from local aussie ebay seller for about $40) and ran flawlessly ever since. My thinking is when the engine is cold, its not relying on the o2 sensor to adjust fueling, therefore it runs fine up until the engine warms up (blue sensor). Faulty o2 sensor kicks in and causing fueling to be all over the place (mine was over fueling).

That's sounds right for an O2, if the car starts unplugged then it's probably not the cause though. I bought a new coil when diagnosing a dead ECU, Autobarn can get them.

[bigt]

Thanks for that, just going to take you through what has happened today.

Ok first of all Autobarn are muppets, they sent me the wrong fuel pump after paying for express shipping even though I gave them part number and confirmed twice!!! then they said they will check again with the supplier...

Second the car starts with the BTS in, only when it reaches operating temperature the car will cut out.

The lambda(o2) sensor has been replaced.

Third the ECU is not dead as it is brand new(from uk). It is a digifant 2 as was my old one.

Coil is last on the list although I don't see how this is causing the issue as the car runs fine with the BTS unplugged.

Vacuum leaks have been checked and turns up bubkis....

Any who that the state of play and I am beyond rope-able atm....

[OEM G60]

Genuine VAG BTS?

[bigt]

Yes, ordered through VW moorabin dealer.

[The Fonz]

Mmmmm.... this is interesting....

you've checked everything twice and still no joy... do you have a mechanic that specialises in Dubbs that can look at it for you or the other choice is (I cant believe im going to this) take it to the dealer to sus out

[martinijosh]

Re: Bigt's Big MK 2 project temperature problems.

Apprentice mechanic won't know anything about his mk2

[bigt]

taken it to vw and have have had a mechanic from vw working on it....

Next step is an auto elec