Car Broke down! :/ after full revs Any help /advice?

[twoqu]

Seems the ecu would not like anything above 16V. Only the ecu could tell us that happened!
Possibily an issue with the injectors as they would be on fuse 28 and also interconnected via the the holding relay to fuse 27. Perhaps one or more is stuck open.
Not sure of the spec of the car so not sure whether they are stock or not. If you have a multimeter you could check accross the injector terminas and post the result.

[twoqu]

As Mike has said S27 is fused directly from the battery not ign. It is to provide power when the engine is shut off for the maf burn off and presumably the ecu memory.
I think this might be an issue with the infamous holding relay. Its a bit complicated but before the engine starts the relay provides power to things like the fuel injectors and when when the ecu is happy it takes over via the fuel pump relay.
I'll have to do some more homework but in the meantime disconnect the MAFand the fuel injectors and see if that makes a difference. If you have enough fuses do it one at a time. That might cause codes for those but its probably academic now as to whats happened.

[Mikes2]

fuse 27 goes to the ecu pin 18. I suspect the problem is on the other side of the circuit (L30) - http://s2-audi.co.uk/workshop/schema..._aby/page7.png

[Vauhtiveikko]

That box is rear locking diff controller and that blue/white wire you want to cut if you want to keep the rear diff locked also in higher speeds. (Its for vehicle speed).

Forget that and first check alternator and starter wires. Also check engine grounding from right bottomside of engine (finger size wires). Then change those fuses and look for codes. Also check as pointed out how spark plugs look and that engine is turning freely.

[Chris5044]

Hey So I have found that something is blowing the fuse I am pointing at in the picture. Initially it was both of those fuses under that orange clip. But its only the one pointed at now everytime I turn iginition to on, (before engine turn over).

On inspection of rear battery under seat I have seen this white cable snipped too.. is this related? or what is that?

I'm guessing I will have to trace the cable now from this main fuse -- the alternator possibly shorting things out isnt an issue as its all sealed (cabling that i looked at). I've now fastened it away. I think the bulb just went on the light issue as a coincidence.

Anyone any ideas on how to fix this? or fault find?? I cant even plug the dianostics in as its not connecting (prob due to this fuse being out) :/ S2 deffo not going to the nurburgring.

thx guys :/

[newsh]

If something is shorting in the alternator charging loom that could cause a spike in voltage.

[twoqu]

OK, just checking as those fuses might indicate something else. Obvious first step is to replace those fuses. If they blow straight away then that might indicate an electrical problem with the ecu. Replace them one at a time, S27 first as thats the ecu supply which should allow you to access the ecu.
Can't see how the headlights would have anything to do with the engine to be honest!

http://www.s2central.com/motronic_04_fuses_ABY.html

[Chris5044]

Fuse 24 is for engine bits like ISV and Fuse 25 is for the lambda. Do you mean Fuse 27 and 28?

Its not completely accurate, but its the 2 fuses that are separate and contained within the motor cap, that also covers those fuses, they face you sideways compared to the other fuses. (facing a different direction). (positioned central in fuse box, but closest to the front of the car)

thx for advice other dudes!

[twoqu]

Fuse 24 is for engine bits like ISV and Fuse 25 is for the lambda. Do you mean Fuse 27 and 28?

[steve briance]

why not elimnate known faults while you are getting to the bottom of the problem, you never know - it might just work

[Bowie69]

I assume you have checked the wiring you talk about?

We can't keep going just guessing, you do need to look at the car yourself as well.

[steve briance]

The aby has an electric water pump to circulate water on shutting down the engine so you could hear water circulating. It stops hot spots and heat soak into sensitive components.

Have you been able to check the belt / crank pulley condition / do compression test? Take spark plugs out (just to make it easier to turn as not fighting compression) and try putting socket on crank pulley and turning over by hand. With the plugs out you should be able to feel any resistance due to valves not being in the right places. If it won't turn over by hand or turns then suddenly stops, stop and think again.

[Chris5044]

Hey Guys!

So today / yesterday I discovered that fuses 24 and 25 had blown, (motor fuses and timing etc) I'm still not sure what caused this. The front left lights are still dead and making weird sounds when I turn on the ignition, but I did remember accidentally breaking off the holder for a few cables that lead to the front left lights. They were concerningly close to the alternator just dangling, could this have shorted the whole system?

Also when ignition is on I can hear water moving near the top of my radiator through the water pipes there, what is this???

water pump? but its surely not on without the engine?!

(Ps: ecu couldnt be checked as fuses power the ecu that went down).

[Chris5044]

This happened to me yesterday in my shortened UR which has an ADU engine in it...………

On the way home though and after a hard exit in 2nd from a roundabout, the engine cut out and I had to roll down to the bottom of the hill before parking safely. Fortunately I took the OBDII code reader with me having previously rewired the connectors so that I can now get live data. The only code I could pull was 'overcurrent'.

The car would turn over but not start. I initially checked for loose boost hoses and having burnt my arm on the Lamda sensor I sat back in the car for a re-think. So, checking fuse 13 (Fuel pump) showed that it had blown. I then swapped this for fuse 17 (Heater/blower) and the car started and drove 100 meters or so before cutting out.

This time the fuse had now blown, so I removed the fuel pump relay and plugged in the jumper wire which effectively bridges/links 12V's directly to the fuel pump. I could neither hear nor feel anything from the pump.

After another ponder, I lifted the back seat and checked the connector and noticed that the green and yellow wire was tarnished from heat over the last 37 years and this is where it gets interesting. Both connectors/wires were attached, but the wiring felt so brittle. I can only presume that although there was a connection, it was impaired by the amount of carbon on the wires and effectively caused a bad connection, causing more amps to be drawn.

I then looked around this fairly remote area and knocked on the door of the house which had loads of old Jags parked on the driveway and guess what, he was a mechanic of 50 years and had a wire stripper and some connector block. 5 minutes later I trimmed back 10mm either side of the wiring and made temporary repairs and the car fired straight up and the journey continued home.

Reason for posting, well, check the wiring around the connector and make good before it lets you down.

Sounds interesting!!

For everyone else my 2x2 adaptor eventually arrived today so I can link to my OBD2 reader , so ill check the code today, whilst taking on board all of your ideas / suggestions and experiences.

Huge thank you guys, that is very selfess of you to help and reply and provide assistance and lknowledge through your experiences, I am truly grateful.

Will report soon, I have all stopped also as was trying to get it up and running for nurburgring trip end of month and it was consumming my life and I literally have no garage...working into the evenings, also a plus is that Audi tradition have eventualy contacted me and there is a way to obtain parts now through an audi dealer in the uk using audi tradition, Had to do some searching! but wowsers x

Thank you Audi Team Crew!!

(in other news I saw 2 giant Audi R8 race lorries driving down M1 last night .. they looked epic!!)

[steve briance]

What have you found out?