Starting issues

[EcosseGP]

I'm looking for a little help with the car. I've not had it long and it's been a nightmare since buying it.
I have an A3 1.8 T sport on a 2000 "X" registration. The car has a full service history and has covered 146,000 miles.
The car overall is great but I have a problem when initially starting it from cold.
If I start the car from cold and try and drive off it just coughs and splitters and I get no power at all making it almost impossible to drive.
However, if I start the car and let it warm up (ie until the automatic choke comes off and revs drop) then the car runs sweet as you like. There are no other running issues or lights on once the car is warmed up.
Now I've changed the MAF sensor, temperature sensor, the vacuum pipe to the secondary air pump (split), the rocker cover breather hose (split) and a oil hose below the breather hose. Nothing has made any difference and on putting it into the garage they say there are no codes being shown for the engine. I had it in before replacing the codes and they cleared them all to see what it would throw up after sorting the above problems. The dash temperature gauge does work but goes up very slowly ..
Does anyone know how I can solve this start up issue it's driving me mad ..thanks in advance

[immynanj]

Im no expert, but i had similar issues although it was not only when starting and it was the throttle body, sometimes a good clean will fix it but you will need vagcom to reset it. Also check coil packs as these are known to go i have a couple of spares somewhere around if your any where near me n wanna try swapping em over.

[EcosseGP]

Ok I'll check the throttle body and see if it makes any difference after a good clean. Is it an easy job and can you point me in the direction of it and what I should be ensuring is clean ..
If that doesn't work might get back to you if you've coil packs to try/sell.


At 8000rpm no one hears you scream

[EcosseGP]

Ok just managed to get round to checking the throttle body and have given it a good clean along with the air temperature sensor beside the throttle body. I have to say it wasn't too dirty but it hasn't made any difference at all .. What should I do next to solve this dilemma ? Would changing the bosch air temperature sensor (number 058905379) make any difference and how could I check that it's working correctly before changing it ?


At 8000rpm no one hears you scream

[95cabrio]

oh dear, you have taken it to a garage and they have plugged it in and it says there are no errors?? when clearly there is an error?

if hand on heart the car runs sweet when warmed up then i am thinking you may have an issue with your ecu hence why no codes are showing up.

how often do you change the pollen filter on the car? a common problem on the A3 is that if it isnt done often moisture can fly in through the vents and in some cases actual water seep in and affect the ECU. fortunately you can get it repaired if it is at fault.

[EcosseGP]

TBH I've not changed the pollen filter on the car as I've only had it from November. Do you think it's worth replacing the filter ? Never considered that ..


At 8000rpm no one hears you scream

[EcosseGP]

Just wish it would show a fault code so I'd have somewhere to start in my quest to get the problem sorted !!


At 8000rpm no one hears you scream

[95cabrio]

mate as i keep saying, if the ECU is showing no fault but there is something wrong with the car then your ECU has a problem! simples

[EcosseGP]

Oh well maybe need to try source an ECU for it then .. That'll not be cheap


At 8000rpm no one hears you scream

[NickPicks]

There are quite a few faults that won't show up on a fault scan. The ignition module / coil packs don't. nor does a dirty throttle body, and if the temperature sensors are wrong but feasible, the the ecu won't recognise it as a problem.

You say you replaced the MAF. Where did you get the new one from? I ask because Crasher here says that aftermarket MAFs often arrive faulty, and you should only use genuine VAG ones (I've never had to replace one, so I can't comment.)

If you have a laptop and a vagcom cable (about £20 from gendan), and a shareware version of vcds (about £50 to register), then you can use measuring blocks to see what temperature the ecu thinks it is when it's cold (I'm not sure if you can do this with the unregistered shareware version).

There's also another thread in this section about clearing the 'learned values' from the ecu which might help with the spluttering. (Edit - you've already found that and posted on it)