Audi A6 Avant Ignition no-go!.

...or the battery is flat. Just a thought.

Which engine?!?!

If its the inline 4 2litre, then almost certainly its the amp mounted under /next to the coil.

Tim..

unless you introduce a condenser as well then you will only get a feeble spark.

is the cambelt still intact and turning? they usually fail at start up.

otherwise it is connections, immobiliser, crank sensor, ign module, etc.

if you are in the aa get them out.

mrcheerful

In article , mrcheerful . writes

Yes in fact further experimentation revealed that adding a cap across the coil did indeed get it better. But in the original design thats not there is it?, it seems that the ignition amplifier is just a simple semi conductor switch that takes the output of the ECU and "amplifies" the switching pulse from that..

Just a well they fail then!!. The distributor is going round so its OK..

Yep,

Actually went back to site this am and re fitted coil etc and switched on and started first time and been running ever since!. Took a scope to the ign amp input and output and very much as expected low amplitude slightly sloped pulse and on the output side much larger with some ripple and overshoot and big fat sparks!..

Mystery. absolute mystery!,suppose something is intermittent or the immobiliser has got its nickers in a twist. Wonder if it might be due to being parked right next to a radio transmitter site, 'tho nothing would have changed since yesterday afternoon!!!..

Thanks to all who replied on group and via e-mail!....

: Yes in fact further experimentation revealed that adding a cap across the coil : did indeed get it better. But in the original design thats not there is it?, : it seems that the ignition amplifier is just a simple semi conductor switch : that takes the output of the ECU and "amplifies" the switching pulse from : that..

I'm pretty sure there will be a big capacitor somewhere in the ignition amplifier.

Ian

In article , Ian Johnston writes

Can't be all that much as there seems sod all room in that unit!

cheers

No, as the ECU performs the condensor-esque control of the LT side of the coil.

Tim..

In article , Tim.. writes

Err right;!, when is the ECU anyway?...

When is the ECU. Most of the time I would think...

Under the scuttle panel, base of the windscreen passenger side. Be very sure it is not cracked / damaged and replaced properly as I've known several die from water ingress caused from broken / missing panel.

Tim..

Modern car HT systems don't just switch the volts to the LT side of the coil - likely to be a capacitive discharge type?

Just let you all know, if it is the coil pack that is faulty VAG now give a lifetime warranty on Coil Packs & Air Bags

Our 2002 VW Golf 1.8T with 185,000 miles had a faulty Coil Pack last week & we contacted VW Customer Services after remember the thing about Audi's & enquired if they offered anything as a gesture of goodwill & we were told by Customer Services that it would be replaced by our local VW dealer FOC which was done on Thursday

In article , A C writes

Actually its been fine ever since the other day!!!.

Perhaps there was a UFO nearby that was sucking all the power out of the air;-)

In article , tony sayer writes

O dear!, same again. Have my suspicions that the immobiliser may have something to do with this!.

Anyone know where its kept?, bl**dy Haynes manual isn't any help, just saying "refer to your VAG dealer";-!....

It's built into the enginemanagement system. You can extract the codes with Vag-Com or any decent independent VW garage can do so.

Thanks for that. In fact I had a vehicle sparks round today and once again its behaving itself!!, though the did say there were problems in its memory with a few things and didn't want to justify changing them on spec, so he's deleted the "history" and said if it packs up somewhere just call and he'll come along and read it again!....

And as a follow up to this one. Vehicle sparks fitted a new ignition switch as he said that the contacts were a known problem and sure enough they did look rather burnt and manky and, there was an Audi recall on vehicles from that year, which was alleged to cause some problems this motah had experenc3ed over the years odd shenanigans with windows and flashers etc, and I don't think this one was done.

Anyway drove around fine till Saturday nite when it cut out and came back and then cut out again and wouldn't restart. Towed home as was only just down the road. Wouldn't start when cold few tests were done distributor pronounced finally deceased new one fitted and all is fine now so fingers crossed:)

And thats to all who replied....