VASK Forum (VW Audi SportKlub of NZ)

GENERAL => Technical Stuff => Topic started by: Pushbutton_auto on October 02, 2020, 07:10:40 PM

Title: Battery swap, now no fire (Audi S8)
Post by: Pushbutton_auto on October 02, 2020, 07:10:40 PM
Swapped out the battery (Audi 2000 S8) today, now no start, cranking strongly (for now) but no firing. Got gas and new battery, so its probably something computer wise (stopping gas and/or spark). 
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: le mans on October 02, 2020, 07:41:03 PM
At a wild guess I?d say it?s a coincidence and you?ve got an issue with fuel pump or crank signal. Don?t think these old cars need recoding after a battery change but could be wrong.
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: Pushbutton_auto on October 03, 2020, 12:02:26 AM
That is what I thought about recoding, tho we still have hassle with the keys on the old cars ...

But I don't do coinciding ...  :laugh:  ...  If it drives when I parked it, it WILL DRIVE away   ...  :laugh:  :)  :laugh:


Tomorrow waits .....   
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: Gordo on October 03, 2020, 05:50:22 AM
Have a good look at the cables for the battery, and around them - you may have missed connecting up something that can undone when the cables were pulled off the battery terminal(s).
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: rambo_005 on October 03, 2020, 07:17:19 AM
Checked fuses?
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: Pushbutton_auto on October 03, 2020, 10:47:59 AM
Only wires attached were a pair of yellow wires one to each post. I thought this was the alarm ?

There is that lonely brown wire by negative, but it wasn't attached to the battery when I took the cables off.

Anyhow Sun has risen above the hill, so I will warm everything up and give a few more cranks, then move on to starter fluid and fuse checks.

The main display looks normal, no odd lights or signals ... so heres hoping ...........  8)
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: Pushbutton_auto on October 03, 2020, 11:10:19 AM
Ok, I got a stumble like it wanted to go but then nothing again.   

Gonna get more gas ...  Just noticed the gas tank reading is rock steady LEFT.

So maybe its the fuel pump playing up or some thing that can't read the true gas level.

Early lunch for now, then one more go before the afternoon activities commence  .....  :angel:
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: le mans on October 05, 2020, 11:22:51 AM
Any luck?
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: Pushbutton_auto on October 05, 2020, 12:39:25 PM
3rd round in ten minutes ....  :-\

Last night the first time I tried it felt like it rolled over, just the pistons ? no spark-fuel, weirdest sound/feeling I have heard for a while. 

If no action today (New battery is weakening) then I will jump start the two other cars with it before it flattens  ....

So FUDGING annoying, ($380 for the new batt) I would have had everything sorted in an hour and laying back drinking a few Reds, if the bitch kicked the other day.

Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: Pushbutton_auto on October 05, 2020, 12:42:15 PM

Otherwise its back to the basics, check the fuel flow, spark etc  ...  ::)
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: le mans on October 05, 2020, 03:22:31 PM
Bugger. Might be worth grabbing a cheap scan tool and scanning it for trouble code(s)? Got plenty of fuel in it?
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: Pushbutton_auto on October 05, 2020, 03:52:29 PM
todays update,

after rumbling a little once more, it was back to nothing - just starter

But now I have a loud whine from the boot ?  Fuel pump ? 
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: 80 Vert on October 05, 2020, 08:13:36 PM
You've confirmed you have fuel?
While cranking have someone listen if the fuel pump is running.
I had a 928 that would stumble once then nothing, bad fuel pump. Pump worked but didn't have enough pressure for engine to run.
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: Pushbutton_auto on October 05, 2020, 08:46:56 PM
Yeah sounds like it,

not up on injectors, but seem to remember others having similar problem, where the injector would leak a touch of gas then no more. 
Title: Re: Battery swap, now no fire (Audi 2001 S8)
Post by: Pushbutton_auto on December 01, 2020, 05:06:24 PM
Well, after forgetting the car for a few weeks, I took the new (4 wk) battery back, to get him to recharge it. He applies the multi to the battery and announces that its fully charged  !!!!!

Now from what I remember (u should always work on cars continuous  :laugh:)  the last time I tried to turn it over, it did NOTHING, so I assumed the new battery had just flattened after a couple days of cranking, but apparently not.

Not working on it today, even though the BIG RED Bike Run is on this Saturday ...  >:D  :laugh:  >:D.
So i will give a better update tomorrow ..... gawd, it's gonna be good to blow the cobwebs out .. (me and d car) >:D
Title: Re: Battery swap, now no fire (Audi S8)
Post by: Trofeo on December 01, 2020, 06:48:27 PM
You mentioned earlier there were yellow alarm wires connected to the battery? Do you have an aftermarket alarm? And if so, could it have reset to the armed state therefore preventing the car to start? Maybe a lock/unlock cycle is required with the keyfob?