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Discussion Starter · #1 ·
I recently put a small amount of petrol in my diesel 2.7 audi a5. It cut out on me and wouldn't start again. I have drained the tank. Changed the filter. Changed the glow plugs and checked all the injectors. With this all being done I am still struggling to get the car to start. Fuel pressure all good and fuel has been force bled using diagnostic tools. No faults codes showing either.
Please can anyone tell me if there is anything else I can check to see if that would fix the issue
 

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Audi A5 f5 3.0 TDI Quattro S line S tronic Virtual Cockpit Driving assist pack
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Hi,

I can only assume you circulated the fuel into your system, if the car had to cut out midway!

Petrol will act as a solvent, damaging the fuel pump and other parts of the fuel system so replacement of the fuel pump, diesel injectors, filters and maybe even fuel tank....

May have to change the fuel injectors in this case too! That alone is a tidy sum, so maybe go to an indie garage to have a look at first if you’ve done majority and still scratching your head!

let us know how you get on! 🤞🏻
~Alex
 

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Discussion Starter · #3 ·
Yeah that's what I'm a little worries about as cost of all parts seem to be very expensive. I tested the fuel pressure and that all seems good and pretty much tested everything and still having the issues. I am tempted to replace all 6 injectors although they seem to be okay and then seeing what happens. I can get it to fire on easy start but it only fires with that and stops once easy start has stopped being used. Even got a couple licam mechanics scratching their heads about this one
 

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Audi A5 f5 3.0 TDI Quattro S line S tronic Virtual Cockpit Driving assist pack
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I’m just surprised no fault codes are being thrown here at all.

If the engine is turning with easy start and then proceeds to stop once it’s stopped being supplied, I’m wondering if it’s the fuel injection system.

I mean do you remember how much petrol you put into it?!

Going through the fuel system again and making sure last bits of petrol pushed out!

A point worth bearing in mind here is that diesel & petrol may not have mixed homogenously (in other words, evenly), therefore a quantity of neat petrol could have been ingested by the fuel system. So may need to check compression aswell to see if your engine can even hold compression... if there was enough petrol that went into your engine as it may of FUBARed it.. 😭

Sorry to be bearer of bad news! But there’s a lot that could’ve happened as the Diesel engines does consume the fuel as lubricant to engine itself, where the petrol engines does zero on that.

~Alex
 
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