Help with A8 non start issue

[Singh]

Thanks, guys. I'll try disconnecting the pump and see if it still blows, btw - there is a 15A in there at the moment and I have been replacing it with a 15A each time I re-try with more fuel/different time of day, I'm sure that's also what it said on the inside of the fuse box, unless I read it wrong? Should it be 30A? Hopefully, it is that simple...

[ainarssems]

It could well be that it is meant to be 15A, I just though from memory that it's supposed to be higher value. If it says 15A on the sticker then it's 15A.

[Singh]

Yes, 15A, the other A8 is 15A too. Will try the wiring disconnect trick and report back this evening. Anything else it could be or I could try whilst I'm down there?

[Singh]

An update – the ignition switch was knackered, the steering locked and it wouldn’t release, after putting a new switch in, it released straight away and the ignition now has that proper ‘springy’ feel.
Photo of the old switch here:



Car still not starting though, symptoms are as if it has a flat battery, but the battery is fine, so I took off the passenger wheel arch liners and found the fault, the wire going to the starter is bad, gave it a bit of a wiggle (disconnect the battery first), and the car is now trying to crank, not only that, but the fuel pump fuse is no longer blowing either! Some progress…
I
t won’t turn over though, it sounds as if it is being starved of fuel, so I whipped out the old fuel filter and replaced it with a new one – same thing!

Next job is to replace the fuel pump, the last owner replaced this, but with a second hand one, bugs me that does and total false economy, especially since a genuine new Simens VDO ones can be had for nearly half the second hand priced one! Keep your fingers crossed for me, I reckon I could have it working this week.

[green A8]

Have you tried cleaning the earth lead at the front of the car (O/S chassis) Amar? I had all manner of problems similar to yours, lazy starter motor, self opening sunroof and windows ect. That was caused by one pesky corroded earth lead, since cleaning it at both ends all the electrical problems on the car have vanished. I cheated and added a second lead whilst I was in fixing mode

To complicate matters my car is dual fuel LPG/petrol. The installers had run the LPG supply pipes very close to the plastic petrol pipe in the engine bay and over tightened one clamp. Result? slightly crushed petrol pipe, and somewhat restricted petrol supply to engine.

Hope this helps.

Paul.

[Singh]

Paul, I believe we are talking about the same wire, although mine had no bearings on the other electrical items, they worked fine, it was just the starter motor not getting any power.

I don't believe it is a crushed fuel pipe as the car hasn’t been LPG'd, so reckon that's unlikely, it could be a badly fitted fuel pump, although the ex owner said he replaced the fuel pump, I don't know whether he had it running on this one or not. I'm about to order the new Simens VDO one regardless, I don't see the point in replacing an 18 year old fuel pump that has failed, with another 18 year old one that is likely to fail.

[green A8]

I couldn't agree more with your above fuel pump comment Amar, the problem with some owners is that they are running the car on a shoestring and when a fault develops they opt for the cheapest fix that they can find. My motto is 'fix it once, fix it right' That usually means add new parts, not unknown second hand ones. it might cost more but saves on flustration and repeating repairs.

I'd tend to have a look at getting a new pump relay as well ae fitting a new fuel pump. That way you know that you've sorted the problem once and for all. I'm looking forward to reading that the car is up and running and congratulating you on a job well done

Paul.