VW Golf 1.9 TDI 2008 problem

Robbie_2020

My cars has randomly konked on me on three separate occasions over the last year.
1. In third gear - car konked and wouldn't start again. No battery or alternator issues. Mechanic changed the fuel filter as it was dirty. Worked for about 2 months.
2. In netural ticking over. Mechanic sprayed 'easy start' into the air filter. That got it going again. Worked for another 4/5 months. Mechanic put a tube of liquid into the fuel tank that breaks down any sediment in the tank and also cleans the fuel lines.
3. After a 5 min drive I parked up and turned off the car. Came back 2 mins later and it wouldn't start. I used the 'easy start' spray again to get it going.

I've had a lot of different opinions but nothing solid to go on yet. Is there anyone here that can help? It's a solid car but it could let me down anywhere at any time

mad-for-tar

Looks like first of all you’d need to get laptop plugged in and get a scan of engine fault codes to see if anything there is stopping it from starting.

When it’s not starting, is it that the engine is turning over and not firing or that it’s not turning over at all? Depending on which scenario, depends on whether mechanical or electrical issue or combination of both.

Shouldn’t be using easy start only as a complete last resort if everything else fails. Shouldn’t also really need fuel tank cleaner unless having fuel quality issues and/or algae build up but generally plastic tanks don’t suffer those problems so much.
There’s also an electric priming pump in the fuel tank that should run when ignition is switched on, even if it’s only for a few seconds. Pull up base of back seat and see if you can hear it when ignition is switched on.

Even get a proper service done on it if it hasn’t been done in a long time or no record of it. Have you engine management light on the dash with engine running or any other warning lamps that normally shouldn’t be on?

Robbie_2020

mad-for-tar wrote: »

Looks like first of all you’d need to get laptop plugged in and get a scan of engine fault codes to see if anything there is stopping it from starting.

When it’s not starting, is it that the engine is turning over and not firing or that it’s not turning over at all? Depending on which scenario, depends on whether mechanical or electrical issue or combination of both.

Shouldn’t be using easy start only as a complete last resort if everything else fails. Shouldn’t also really need fuel tank cleaner unless having fuel quality issues and/or algae build up but generally plastic tanks don’t suffer those problems so much.
There’s also an electric priming pump in the fuel tank that should run when ignition is switched on, even if it’s only for a few seconds. Pull up base of back seat and see if you can hear it when ignition is switched on.

Even get a proper service done on it if it hasn’t been done in a long time or no record of it. Have you engine management light on the dash with engine running or any other warning lamps that normally shouldn’t be on?

When it's plugged in it shows no error codes. There are also no warning lights on the dash. When I turn it on, it turns over but doesn't fire up. The fuel pump under the back seat seems to be fine too. The car gets a service before the NCT every year. My sibling had it for 9 years without any issues.

From what I gather from online forums, it seems like it the power supply relay needs to be replaced. What do you think?