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Petrol going down so quick like there is a leak!!

Posted: Sat Oct 30, 2021 7:30 pm
by Simonsen
Hi all I have 2.0 tsi rocco cczb engine and I need to diagnose a problem. Petrol is going down like there is a leak obviously there no leak but what could be the issue? Hpfp leaking? Injectors are open? Pcv? I mean I have no dash lights, power delivery is OK I had one fault intake flaps but this has been erased and never came back. Done 20 miles and I've lost quarter of the tank.

Re: Petrol going down so quick like there is a leak!!

Posted: Sun Nov 07, 2021 3:50 pm
by Simonsen
I have two fault codes p2004 and p2015 both related to intake flaps, fuel pressure rail shows 40 bar so bang on no other faults. Can't smell any petrol in oil so I am ruling out hpfp, lambda control adaptations show - 2% and idle and - 6% at revs so maf and lambda sensors are ok. I am thinking injectors are failing. Any suggestions??

Re: Petrol going down so quick like there is a leak!!

Posted: Sun Nov 07, 2021 6:20 pm
by chelspeed
Bit of lateral thinking….. Faulty fuel gauge?

Fuel has to be somewhere. Either still in the tank (failed sender as above), leaking onto the ground which you would see or going into the engine perhaps as you suggest via failed hpfp or injectors.

Lets work it out, 20 miles should use about 4 litres, quarter of a tank is 20 litres or thereabouts, so you would be overfuelling by 5 times. If that much fuel was going into the engine then theres no way “power delivery is OK” could be said. It would be coughing and spluttering, black smoke and smelly (unburnt fuel) exhaust.

So I reckon something else is happening.

So keep searching and let us know.

Re: Petrol going down so quick like there is a leak!!

Posted: Sun Nov 07, 2021 8:22 pm
by Simonsen
Thanks for reply.
Definitely no leaks and definitely no issues with sender.
There is a lot of black soot around tail pipes.
While I had chain kit changed I had injectors cleaned in ultrasonic bath i am wondering if that damaged them?
Maybe they are stuck open but then I would have some misfires?
My problem is all potential causes are expensive lol

Re: Petrol going down so quick like there is a leak!!

Posted: Tue Nov 09, 2021 8:50 pm
by a4gee
Mine did this but was shaking and struggled pulling away. Had to replace injectors - didn't waste time getting them checked to see which one was wrong. Also the inlets were choked with carbon etc and had to get cleaned as the engine can't get rid of it.