1995 Audi A6 2.8 12v stops. And starts, wahey! :D

[Deleted]

Hullo, i've aquired a 95 Audi A6 2.8 Quattro, wich seems to have issues with stopping for no reason. It loses spark, but if you wait a little, it starts up again just fine. Also, whenever i turn the ignition on, the driver side window goes down a little, wich seems strange to me. I got it for free because of said issues, but would be a shame just to scrap it, since its basically got all the toys except el. rear windows, and would make a nice runaround. Its an automatic, if that makes any difference.

Having a few mates with Audi's, i'm tempted to think its the coil pack, since these seem single-use-only on Audis

[joe90]

Does it definitely loose spark, early 90's Audi' were bad on fuel pumps, run for a while, then stick on tick over or not run then start and run for a while then go through it again.

Bryan

[Deleted]

It does seem to lose spark, but the coilpack is said to be new, and doesnt get hot or anything like that, so i suppose the cam\crank sensors could be bugging up? But i'm not 100%, so i'll check the fuel pump too, thanks for the tip!

[bortaf]

Coil packs are basicly 2 double ended coils so for it to go totaly both need to go at the same time, then come back together? not the usuall way it happens IME.
If it's the CPS there will be a fault code logged, have it code read a see what comes up ? could be a cam sensor but they only get used for starting, they don't stop the engine but will stop it starting if you follow me ?

[SauceDoctor]

Any fault codes?

These things are known to eat engine relays, and ISTR a short to positive fault on the relay that controls the ECM.

[Deleted]

Yeah yeah, i'm slow, i know. I've changed the fuel pump relay, but didnt seem like that was it, but at least its got the larger relay they put in there in the later models.. It definatly gets fuel, but now it wont start at all, seems like its a problem that occurs when its really cold. But no spark at all, so gonna borrow a fault code reader and see what comes up

[Deleted]

It started, briefly, but when i check the plugs, they are bone dry. It gets good spark consistently, but the injectors doesnt seem to be opening, thinking the ECU might be bad. Or could the injector relay cause that too?

[Deleted]

Newest update (no i havent gotten hold of a fault code reader, the one my friend has is borrowed out elsewhere..), it starts and runs as nice as when its really cold, as soon as the car starts thawing up inside it cuts out again. Gonna dismantle the brain to see if its full of water tomorrow, if the weather allows. (Webasto, so it gets warm inside the car long before the engine gets warm. Yet another reason to get it running, in these cold times!)

[Clement]

it starts and runs as nice as when its really cold, as soon as the car starts thawing up inside it cuts out again.

I've had this on the Maser, and it was caused by a dead water temp sensor. Basically the ECU doesn't know that the engine is getting warm and after a few minutes of nice cold idle it just dies and is really difficult to restart.
It doesn't really correspond to the other symptoms though, I'd have said the fuel pump was toast at the start of the thread but now I'm confused.

Blocked fuel filter maybe?

[Deleted]

I've got a cam sensor and fuel filter in the mail, figured i'd might as well put some new stuff on it. I forgot to say that when it was warmer outside, it would barely run, it only starts and runs when there are several degrees below freezing outside. Newfangled electrickery, give me a iced over carburettor any day, haha!

[Deleted]

So it turned out to be A: A busted fuel pump, it would cut out after a little while. And B: A busted cam sensor. So i'm thinking the cam sensor caused the non-starting bit, and the fuel pump caused the stopping while running bit. Time for a EU control, lets see what else is wrong! ...oh, and putting all those plastic covers back into place EVERYWHERE