allroad tdi 2.5 air in fuel :(

[m6rk]

When parked on an incline or after going up ramps etc the car won't start

Cracking open the injectors and bleeding it fixes the problem.. I've tried replacing the fuel filter but that hasn't fixed it

Any ideas? Can't see any leaks anywhere and fuel economy seems as average as ever..

[mbeston]

Have same issue & still not found root cause. The problem appears to be pressure build up in the tank. If I leave my fuel cap loose the problem disappears.

There should be no need to crack the injectors. If mine stops after parking on incline I find the cap has self tightened so opening it and cranking gets it restarted.

[m6rk]

really appreciate the reply.. will try that next time!!

I'll ask my audi-tech mate and see if it could be something to do with the tank-gas evap system thingy..

[brickit]

Check your lift pump in the fuel tank. Mine stopped working but car still ran but lots of air in fuel line ( you can see throughr the clear pipe nr. the VE pump.) £600 from *********** - now OK.

[m6rk]

so whats the easiest way to check my lifter pump?

[Peter D]

Rocket science. Can you hear it running in the tank filler for the first few seconds. ???

https://www.vwaudiforum.co.uk/forum/s...ad.php?t=13380

Regards

Peter

[brickit]

Mine was running but it did not deliver any fuel.
You can disconnect the input to the fuel filter and crank the engine, diesel should come out.

[a8 tech]

Ask him to have a look at the archive technical solutions if he works for audi main dealer,there is some info on this but if i remember there was never a fix but the symptom was accepted(fuel pick ups at the front of the tank hence fuel movement allows air to be drawn instead of fuel when parked on an incline)always leave more than than a quarter full.

[m6rk]

well it has been ok and now started playing up

tried leaving the filler cap open but no joy.. booked into a good independant dealer on tuesday so fingers crossed..

I don't understand though how a failing pump would allow air into the system, especially if it's a submerged type..

[a8 tech]

Attachment 1000On vehicles with four-wheel drive the fuel tank is divided into a left and a right chamber.
t A so-called suction-jet pump -item 6- (left-side) is used for delivering the fuel from the left fuel tank chamber to the baffle housing of the fuel delivery unit -item 4- on the right.
t A second suction-jet pump -item 1- is located in the right fuel tank chamber and serves to improve the fuel delivery in the right fuel tank chamber to the baffle housing of the fuel delivery unit.
t The suction-jet pumps operate according to the principle of fluid entrainment: a stream of fuel delivered from the fuel pump fitted exclusively for this purpose -item 7- is passed through a nozzle in the suction-jet pumps -item 1- and -item 6-, and is thus accelerated. The accelerated stream of fuel draws off the surrounding fuel and delivers it to the baffle housing of the fuel delivery unit. The right suction-jet pump -item 1- delivers the fuel directly into the baffle housing, the left suction-jet pump -item 6- delivers the fuel via a separate pipe -item 5-.
t The fuel is distributed from the fuel pump -item 7- to the two suction-jet pumps via the connecting piece -item 8-. At the same time, the connecting piece restricts the pressure in the pipes to the suction jet pumps. Excess fuel is delivered via the Y-connector -item 2- and directly via another pipe -item 3- to the baffle housing.
t Unlike the system employed for petrol engines, the fuel supply and fuel return pipes to/from the engine are not required for the delivery of fuel to the suction jet pumps. As on vehicles with 6-cylinder engine and front-wheel drive, the injection pump is sufficient to draw off fuel from the baffle housing in the right fuel tank chamber
sorry iam thinking about the complaints when the vehicles were parked on a incline and wouldnt start,there was air being drawn through and eventually fuel.