1998 Audi A6 Check Engine Light & Hard Engine start At

TMADDENJR

MEMBER
1998 AUDI A6

Engine Performance problem
1998 Audi A6 6 cyl All Wheel Drive Automatic 242K miles

My 'Check Engine light came on, the computer read was 'Large vapor leak'. 1st the gas cap was replaced with a new one. Check Engine light stayed off for a couple of days before re-lighting. Next the vacumm pump location in the rear wheel well (driver's side) was replaced, light stayed off for about a week. Now light is back on.

Also at refueling I have to press on the gas pedal to get get the egine started. Once it restarts I don't have any problem restarting with just a turn of the key until the next fuel re-fill.

Any ideal what the problem is?

Thks,

Ted

7 Replies

KHLOW2008

MECHANIC
41,814 POSTS

Hi tmaddenjr,

Cna you provide me with the exact troublecode retrieved?

Does the CEL still indicates while driving?

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Sunday, January 17th, 2010 AT 5:04 AM

TMADDENJR

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4 POSTS

The trouble codes are;

16825 - EVAP Emission Cntrl (incorrect Flow)

16839 - EVAP System (large leak Detected)

The EVAP Purge Value has been checked and is OK

The Leak Pump in rear wheel well has also been replaced.

The CEL remains on while driving.

After every re-fueling I can't start the car with just a turn and release of the key, I have to press the gas pedal to start, maintain a constant pressure on the pedal to keep the car started for about 45 seconds after which the car will stay started.

After that initial start problem I am able to re-start the car with just a turn and release of the key until the next re-fueling.

Thks,

Ted

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Monday, January 18th, 2010 AT 4:56 PM

TMADDENJR

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4 POSTS

The Evap system has been checked out and is OK as previously stated.

The diagnosis per the error codes was performed initially, tests procedures were performed initially also.

Any idea as to why the initial hard to start requiring the gas pedal to be pressed to maintain engine start after each refueling?

Thks,

Ted

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Friday, January 22nd, 2010 AT 11:02 PM

KHLOW2008

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Code 16825 affects the fuel pump and relay operations.
The difficult starting after refuelling is most probaly due to the CEL affecting the operations of the fuel pump and relay circuits.

After refuelling, turn ignition on and listen if the fuel pump whirrs.

I am unable to find any TSB on the problem and diagnostics are vague. The test that I sent you would determine if there are any faults with any of the components that may cause the difficult starting.

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Saturday, January 23rd, 2010 AT 6:56 AM