Hesitation/Misfire problem

earlier ones dont have any such thing as an N249 - just a simple vacuum line to the throttle body... Less to go wrong! Dont understand why you would need something to control the DV anyway!

Rich
 
I changed the air temp sensor today, and its made ****** all difference! Really starting to annoy me now! So far i've changed:

Coolant Temp
Air Temp
Coolant Thermostat
Igniton module
MAF
Spark Plugs

Dont know what else it can be!

Rich
 
Make sure to check their wiring as well.

Today I was driving my fathers '93 Passat and found out that the dash temp gauge is not working. Traced the cause down to dodgy wiring near coolant temp sensor.

This car however also uses the single coolant temp sensor to drive the motronic's single point injection mixture according to the coolant's temp.

With the ignition switched on I moved the wires on top of the sensor and I could hear the motronic adjust.

HTH
Kostas
 
In addition to this thread, I have recently been experiencing cold start problems and some serious misfiring.

I was showing very similar symptoms to RichA3Turbo's problems where its worse when cold, and it gradually developed into being constant (or it could be because its been cold for a week now).

Anyway, rang Murrays Direct and they have the coil pack control module on the shelf, and they sent it to me for £79+VAT and it arrived next day.

Fitted it just now and its solved my misfiring problems completely.

Excellent price from Murrays and the solution to my problem certainly....

http://www.murraysdirect.co.uk/
 
Yeah i ahd that issue....but got worse and worse until one day i have to drive home on 3 cylinders....wthat was bad!

After this, i replace the control module, and all was good...but the cold issue persisted...So was a different issue for me.
On the upside, i dont have the problem anymore...it somehow fixerd itself! weird

Rich
 
This still appears to be happening to me (at this time, the big hesitation seems to have gone, which may be linked to the new DV)....any further news anyone (Re: slight hesitation at 2k rpm)?

DV and spark plugs changed..? I have a slight boost leak, would that be the problem, having the breather pipe changed in the morning
 
I was in the same position as you guys, I had a huge missfire problem on boost, VAG-COM didn't bring up any fault codes... I changed so all the major parts, coils, sparks, MAF, N75 and even TIP... ended up wasting £100's... Got my friend to check logs while on boost and sure enough multiple missfres were occuring on boost on one of the system groups while doing a live run...

Anyway still couldn't work it out was. Thankfully I didn't, I took it to APS who had to have it in. (Top service and VERY knowledgleable and friendsly staff, speak to Ed) They dignosed it as my fuel pump of all things, and sure enough once changed it was perfect on boost! They had to use a special machine to test the pressure on it. I'M NOT SAYING it's your fuel pump by the way at all here.

The point im making is you can spend an absolut fortune on parts and diagnosing it and still not resolving it - I would stronly advise you take it to a specialist. Yes it's a bit of bother i.e I had to take a day off work, but in the long run my cars never missed a beat since. Spools up perfectly with no hesitation what so ever - just as an S3 should be!

Believe me I know what its like when your cars not running prroperelly and spent loads on it trying to fix it, it sucks. Just think you'd be far better of taking it to a specialist who can rectify faults VAG doesnt show. Ok I know I keep banging on about APS who were superb for me, but any other specialists with good feedback would be worth considering. If I'd done this the first time round, I would of saved a lot of money, effort and dissapointment - pls consider it mate.

(Essay over! ;0)
 
Cheers for that. I had the weepy breather pipe changed today and the dv was also faulty (changed Sat), so far so good, but will I know the result of these changes by the end of the week.

Thanks for your time on this mate...(will update, as I am sure other will experience similar problems..)
 
I appear to be having the exact same issue, and its rather annoying to say the least, although from reading through various posts, it appears the same symptom can occur for different reasons?
id like to walk through my logic with people that have had this before to see if you come to the same conclusion please.

I have a 1999 1.8T A3, AGU engine with old style coilpacks, and the car intermittently judders at low revs, and lack of umph to accelerate, sitting at idle its not very healthy, puttering so to speak.

>ive been through the coilpack test, however disconnecting all of the coilpacks one at a time gives the same result, more juddering in the engine... so that would imply that my coilpacks and cylinders are fine then?

>If my coilpacks are ok, then in theory the N122 (ignition amp module) should be ok, otherwise the ECU wouldnt be sending the signal to the spark plugs via the coilpacks, and one of the coilpacks would appear to be faulty would it not? I can go through this test if needs be http://forums.audiworld.com/a4/msgs/1594531.phtml
but im not convinved I need to given the other test.

>So considering my car is due for a service and given the above plus symptoms, would it be safe to say its most likely the spark plugs causing a missfire? I could do with changing them but what would people recomend? im not going to be chipping the car or anything, plus might be selling it soon, so just need to get something to fix this issue...

any thoughts? am I way off here? have I missed something?
cheers
 
Did anyone solve this problem for good? I am having the same problems. Hesitation, coolant level warning, occasional hard to start, rough idle, dash temp display up and down. Tried, Ignition amp, maf, spark plugs, coil packs but no joy!

Nick