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Old 7th December 2017, 21:05   #541
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Default Re: "My Car Won't Start" | What To Do

Team, thanks for your help! The problem persist but I have a few to-do's at my end.

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Originally Posted by Aroy View Post
It is either loose contact with ignition coil, or clogged fuel filter. Get both checked.
Ignition coil is fit! Fuel filter was changed a week back. Problem persisted.

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Originally Posted by hserus View Post
Fuel pump / pump relay? Ignition coil?
Fuel pump is good (my car hits highway speeds easily).
Ignition coil again seems to be fine - the RMP dropping to 0 minus mild forced aceleration cannot link to weak ignition coils per my SA.

I've got this done:
1. Sprayed down the throttle body in-place (as a jugaad @ AS$). SA said that if the situation improves (can only be tested properly on a cold engine), then the throttle body needs proper cleaning.
2. I've taken a spare relay to swap with the fuel pumps and ignition relay tomorrow as part of troubleshooting.

Anything troubleshooting tips would be appreciated!
Is it worth cleaning the MAF/O2 sensor? I mean, this is an ignition only issue, but if I am suffering performance-wise elsewhere, I wouldn't know since I just got my hands on this vehicle.

Last edited by bblost : 7th December 2017 at 22:23. Reason: speeding reference edited
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Old 7th December 2017, 21:12   #542
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Default Re: "My Car Won't Start" | What To Do

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Team, thanks for your help! The problem persist but I have a few to-do's at my end.
Just follow Jeroen's advice a few posts earlier and have your SA plug in an OBD-II scanner, search for errors.
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Old 7th December 2017, 22:26   #543
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Just follow Jeroen's advice a few posts earlier and have your SA plug in an OBD-II scanner, search for errors.
Agreed. I shall get on it tomorrow!
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Old 8th December 2017, 13:17   #544
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Default Re: "My Car Won't Start" | What To Do

I older petrol cars it would be Vapour Lock, but in a diesel car that is not the case. All that is left is to check the fuel lines for clogging and or kinks.

I suggest that you also get the compression checked both in a cold engine and in a hot engine, as low compression will not start the engine. The causes for low compression in a hot engine are many.
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Old 8th December 2017, 14:21   #545
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Default Re: "My Car Won't Start" | What To Do

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Agreed. I shall get on it tomorrow!
If you give accelerator input and crank, is the car starting? And will it hold the rev with accelerator input?

If so, clean the throttle body and check if the idle advance circuit is working as it should.
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Old 8th December 2017, 19:46   #546
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Default Re: "My Car Won't Start" | What To Do

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If you give accelerator input and crank, is the car starting? And will it hold the rev with accelerator input?

If so, clean the throttle body and check if the idle advance circuit is working as it should.
Would you suggest the same for my problem?
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Old 8th December 2017, 20:25   #547
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Would you suggest the same for my problem?
Not really. I would rather pursue the mystery below, especially if the error is coming back after clearing it. Do get the tank cleaned also.

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hooked up to service center scanner and found 2 error codes (G40 CAM sensor and G28 engine speed sensor).
Replying from phone. Iíll take another detailed look from the computer and share thoughts if I have further inputs.
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Old 8th December 2017, 20:51   #548
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Crankshaft and or cam shaft sensors are known to cause problems for starting on many cars. You would think this type of sensor works or doesn't work. However, in practice I have seen problems just on starting and idling due to wonky sensors. These are most often induction type of sensors, so the faster the engine runs the more stable the signal is likely to get. Of course, the idea being that the sensors provides a stable enough input even during low rpm.

I would start by carefully inspecting the sensor and its wiring and clean the connectors, see if that makes a difference. Workshop manuals might provide the correct test values, if not you might just want to try to swap.
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Old 8th December 2017, 21:12   #549
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Default Re: "My Car Won't Start" | What To Do

Apart from cam sensor, internet search says temperature sensor, weak starter motor also causes the issue with the older tdi engines. So temperature sensor is also a good place to check further if the engine is turning over well when hot.
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Old 8th December 2017, 21:22   #550
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Quote:
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Apart from cam sensor, internet search says temperature sensor, weak starter motor also causes the issue with the older tdi engines. So temperature sensor is also a good place to check further if the engine is turning over well when hot.

Yes but it would have shown up at an OBD scan and it did not.

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Old 9th December 2017, 01:01   #551
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The temperature sensor that is
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Old 9th December 2017, 10:29   #552
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Default Re: "My Car Won't Start" | What To Do

They say it will not show any errors, but once you replace the sensor it will start fine even when warm. This is an engine specific phenomenon.
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Old 9th December 2017, 13:10   #553
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Default Re: "My Car Won't Start" | What To Do

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They say it will not show any errors, but once you replace the sensor it will start fine even when warm. This is an engine specific phenomenon.
That sounds interesting. So you reckon the CAM sensor and engine speed sensor errors might not be the direct cause?

Can we rule out vapor lock as a reason completely? It's a 2.0 TDi engine (2007 build)
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