1.4TDI 2016 cranks but no start

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ellis8742
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Posts: 1
Joined: Sun Dec 28, 2025 5:36 am
Drives: 6C 1.4TDI
Location: West Sussex

1.4TDI 2016 cranks but no start

Post by ellis8742 »

Hi all,
Recently purchased a 2016 1.4TDI polo, I purchased it knowing it had issues starting and have still yet to find the cause of the now no starting issue. The engine cranks but does not start. When I purchased it, the engine would start but only after a few attempts, when warm it ran fine but then completely cut out 40 minutes after driving.
only fault codes the ECU has pulled is P056200 for system low voltage;
- I've changed the battery.
- Terminal 30 and 15 voltage are both 12.45 and 12.2 volts respectively
- Inspected all engine ground points and performed continuity checks between grounding points / ECU and battery - nil findings
- Checked engine bay fuses/relays, all contacts look in good condition
- Fault code does not clear.. Coil light and EML light on dashboard are very dim, coil light is flashing with ignition set to position 1

Car was occasionally smoky when it did run, but not consistently.

I've checked fuel pressure at rail during cranking, this reaches well above 300BAR - reading via OBD. Inspected the HPFP fuel metering valve and found no swarf. However, with injector pipes cracked there doesn't appear to be a high volume of fuel present.
Continuity between ECU and all 3 injector connectors is okay, resistances okay.

I'm yet to check timing but even with cam sensor disconnected the engine will still not start.
ECU is receiving cam and crank speeds, wiring is again okay..

Has anybody had any previous experience with this?
thanks in advance!
scissa
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Posts: 15
Joined: Fri Jun 06, 2025 8:12 pm
Drives: 6C 2015/5 CJZC
Location: Turkey

Re: 1.4TDI 2016 cranks but no start

Post by scissa »

Is the ground cable okay? Does it crank healthy, did it lose power before cutting out?
What is the voltage while cranking? Does the car has its power while running?

This issue seems like alternator/fuel related to me. These cars have smart alternators, you need to code your battery to your car with proper tools and inspect if the alternator is charging or not while braking.
Cracked pipes on high pressure line doesn't sound healthy, they also cause the issue.

My friend had the same car as yours and he faced similar problem. Cause was dirty fuel and he had to replace pump in the tank and 3 injectors with the fuel filter.
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