Hi Pearl, my VW TSi 1.2 2016 model stalls and there is so...

Hello and welcome to Just Answer My name is \*\*\*\*\* \*\*\*\*\* I've been an automotive engineer since 1996 and together we're going to solve this issue. I understand that having your trusted vehicle let you down can be frustrating as it rarely occurs at a convenient time, however I will do my best to either help you make the repairs yourself or at least understand the issue so you know what is involved. This could be an airleak after the airflow meter, any air dragged in here isn't 'seen' by the ECU and so not compensated for and can lean the engine out causing rough running. As its a mechanical fault it may not to turn on the fault light and you can sometimes hear a 'hissing' noise with the engine running. Check the hose clips for tightness and inspect the trunking for any cracks or splits and also all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best way to locate a leak is to have the engine running and warm and then spray lighter gas /propane or brake cleaner around each joint in turn. If the engine rev's up you've found your leak. Now you might think that spraying lighter gas around a hot engine isn’t wise, however the flash /ignition point of gas is about 400°C so you need a naked flame or spark to set it off and I’ve used this method for many years without incident. Work your way through each possible joint one at a time and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to provide a spraying 'wand' and allow a direct blast of gas into each area, especially those difficult to reach with large implements. Air leaks are very temperature dependent as gaps can open up as things expand with temperature so depending on how the leak occurs ( on a hose joint with a clamp expansion will help seal and on a vacuum hose expansion will make a leak worse) so leaks can be better or worse as the engine warms up 1 vacuum leak path that you won't find with the above test is if the brake servo is leaking so try clamping off servo hose to see if this has any effect It’s also worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a poorly pump will all result in insufficient fuel being delivered to the engine Might also be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a quick fault find if you unplug the meter and run the engine without it. if the engine condition is the same then chances are the meter or the connection to it is faulty It’s also worth cleaning the MAF sensor wires, as they can get coated with dirt over time which then offsets the reading Use some contact cleaner or brake cleaner to spray onto the wires to remove the dirt – on no account touch the wires with anything as they are very fragile

Hi Matt pls show me the the airflow meter sample?

the MAF sensor is built into the air intake of the engine see the attached image, if your's is not exactly like this then don't worry it will be loacted in roughly the same place , so on the air intake pipe between air filter and engine

Thanks for the picture I now have an idea where to checks.I seen three TFS units in the car could it be one of them causing the EPC light warning or the one just over the throttle body unit?Hi Matt the "As its a mechanical fault it may not to turn on the fault light and you can sometimes hear a 'hissing' noise with the engine running". The EPC light is on when the engine is running and there is no hissing noise this couldn't be a mechanical issue?Hi Matt are you still with me?

Hello still here if there's no hissing noise this doesn't men its not a vacuum leak , it may just mean its small enough not to be heard the EPC light being on though means there's a code that can be read off with a scan tool so that shoudl be the next step really as this will give the repair a direction

Noted thank you, \*\*\*\*\* \*\*\*\*\* get the car to the workshop for through checks.

Thank you for your support.

Understood please get back to me on here with what they find