Fuel tank malfunction

[VROOM]

Hello,

Audi A5 2007 3 litre diesel 

May it be noted the car drove from auction to unit about 5 miles no issues.

I have an issue with a car just purchased at auction so don’t know the history of the car. One of the issues is fuel tank malfunction display. After some research I replaced the fuel sender unit under back seat.

At first the car started fine (without moving). Once I completed all my works as it needed new brakes and springs etc the car was ready to go a drive. I barely made it out the unit and the car kept cutting out not wanting to start. Code was low fuel pressure. 
 

When turning the ignition on I couldn’t hear the sender activating so I checked the fuses. Sure enough the third fuse down in middle row for the fuel pump had blown. This was replaced but still the car will not start.

I have tried putting the ignition on several times to bleed the system but still no joy. 
 

When I use Easy Start the car will turn over for a second then just cut out. It’s not firing up for some reason.

Am I missing something?

Thanks for any help 

[Magnet]

Welcome Ryan,

When you say you replaced the fuel sender unit, are you meaning the in-tank fuel pump? 
If so, new ( what brand?) or secondhand? 
 

[VROOM]

4 hours ago, Magnet said:

Welcome Ryan,

When you say you replaced the fuel sender unit, are you meaning the in-tank fuel pump? 
If so, new ( what brand?) or secondhand? 
 

Yes, the in tank pump. Apparently there is 2. I renewed the one under back seat. It was replaced with a second hand one from a car that had been in a crash 

[Steve Q]

Does the replacement unit need coding I wonder? 

Or could it be an issue with the high pressure fuel pump?