Occasionaly not starting Faulty Maf?-

[SnowHammer]

Cars been playing up for a couple of weeks occasionaly not starting and rough running also noticed cant here much sound from the dump valve engine - 1.8t AGU no signs of vac leak but could be possible any advice from vag com measurement below would be appreciated Cheers...

Fault codes:

16500 - Engine Coolant Temp. Sensor (G62): Implausible Signal
P0116 - 35-10 - - - Intermittent

00561 - Mixture Adaptation
14-00 - Adaptation Limit (Add) Exceeded

Vag Com
04: tb 2.6 mass flow -0.24g/s mass flow idle
02: 840prm 1ms2ms 2.76 g/s
06 -3.6% lambda 14.8% lambda 12.0 BTDC

 

[Greg-S3]

Coolant temp sensor is worth changing as that can alter the fuel/air mixture if the car thinks the engine is cooler or warmer than it actually is, I don't think a faulty maf would cause starting issues as the car would run a generic safety map. When you say not starting do you mean it just spins over and doesn't start or spins over longer then doesn't start? Is it worse when it's hot or cold engine wise?

 

[SnowHammer]

Happens more often on a cold engine. Spins over sometimes doesn't quite go , other times spins over for ages and wont start, otherwise starts normally?

Ill change the temp sender this week

Thanks... any other ideas? maybee fueling issue?

 

[<tuffty/>]

The code:
00561 - Mixture Adaptation
14-00 - Adaptation Limit (Add) Exceeded

...suggests there is a massive airleak or the MAF is under reading... adaption (add) means its having to add fuel due to more air than its 'measuring' getting into the engine... lambda only works on idle and cruise on AGU's

<tuffty/>

 

[SnowHammer]

Thanks for the advice,

Will have a good look over for leaks and get the sensors changed this week

 

[RGL]

If changing the temp. sensor and fixing the airleak/MAF doesn't help, then I'd leave the last possible problem to be the fuel pump which lets the fuel flow back into the tank. However start with the faults which you already have clues for. You never know, it more than often is a combination of different faults that makes for these weird issues and symptoms.

 

[basil brush]

My AGU played up for ages , fitted a ECP cooler sensor no better , went right round the houses trying to sort it and in the end fitted a audi coolant sensor and has been good as gold ever since

Baz

 

[vick_79]

anyone solved this problem?
I am having the same error code, have changed pipes vacuum cleaning of injectors, leak testing, changed MAF, changed lambda probe, fuel pressure regulator and nothing worked .. can someone help?

 

[vick_79]

My AGU played up for ages , fitted a ECP cooler sensor no better , went right round the houses trying to sort it and in the end fitted a audi coolant sensor and has been good as gold ever since

Baz

you also had this error?
solved by replacing the temperature sensor?