MY 87 5000 Q, will not turn off. I have the key in my hand and the engine is still running. I have replaced the Ignition switch (it was broken) but the problem still exists. has anyone had or known of this problem. The dash warning lights stay on but all accessorys (heater, radio, ect...) turn off. any ideas as to a fix would be appriciated.

Thanks

Mike

 

did you put the ignition switch the right way? also when this happens press the accelerator and tell what happeed.

 

I rechecked the switch its installed correct (there is only one way for it to go in), and when it is running and the key is out the engine response is just muted not as responsive. also when I turn the key off the engine drops about 200-400 RPM.

 

One thing that I can think of is that perhaps you got a defective ignition switch or the wrong one. Can you put the old one back in and see if that works? Other problems could be either melted wires or fused contacts on a relay(s)? Trouble shooting electrical problems is a major bitch you need a good detailed wiring diagram, lots of patience and strong methodical approach.

 

sounds like a shorted wire to the coil keeping it live "do all dash lights go off with key out" if not there is a short circuit between coil and ignition switch "bad earth/ground"

 

ah, I know what it is. the carbon deposit on cylinders. it ignites the fuel without the spark. usually hapens when you have carburator or mechanical injector with mechanical pump.
becouse their is presure in the system (fuel) injectors work. so it ignates the fuel and doesn't let the engine stop. you can try and put colder spark plugs in that might help. also using highest grade fuel. and using some carbon deposit cleaner like (injector cleaner).
carbon is like coal, when its hot and sprayed fuel and some air it ignites.
also the best way is to just clean the cylinders, but that requires taking off the head.
or instaling cut off switch before the injector distribution.

 

I forgot to ask, this happens when your engine is hot and cold or just hot?

 

ahhh you mean engine over run/run on, timing out/excess carbon build up on pistons would require a decoke but check the timing first, also fuel air mixture setting

 

the new ignition switch acts just like the old. its stays running hot and cold. I think it is a stuck (fused) relay, as the accssesorys turn off but the dash warning lghts stay on. So I think it is a relay. I was told by a local reputable euro mechanic that it could be one of 3 relays or the switch. I do not think that it is carbon build up, diesleing ect... I use Chevron with techron and only Premiun unleaded.
dose anybody know what relays to check? I hate to take it to a shop to have the diagnosis done because I am normally good about diagnostics and I do all of my own maintnance and repairs, but I am new with audi's and dont want to give up yet.

any other ideas?

 

the 5000 was never introduced into the UK but it resembles the 200 turbo if it is I can check it against my data for fuses and relays??