VW UP 1.0 2012 Turns Over But Won't Start

VW UP 1.0 2012 Turns Over But Won't Start

Author
Discussion

dilligaf76

Original Poster:

80 posts

69 months

Friday 7th February
quotequote all
I friend of mine has got this car which was working perfectly fine until they decided to remove the dash and add aftermarket lights and switches by splicing into the wires.
Since putting everything back it won't start. It turns over but it seems there is no spark to the plugs.
What on earth could they have done to cause this?

paul_c123

804 posts

8 months

Friday 7th February
quotequote all
Firstly, how did they determine there is no spark?

For general direction, its worth a diagnostic scan but it sounds like the immobiliser wiring has been disrupted. But it could be 101 things if they've been thrashing around behind the dashboard.

dilligaf76

Original Poster:

80 posts

69 months

Friday 7th February
quotequote all
Well we know it’s getting fuel so if there was a spark it would fire.
Apparently someone did put a diagnostic machine on it but it didn’t give any codes to sag what was wrong.
Is there away to reset the immobiliser providing it is that?

GreenV8S

30,857 posts

299 months

Friday 7th February
quotequote all
dilligaf76 said:
Well we know it’s getting fuel so if there was a spark it would fire.
That seems like quite a big assumption.

If you haven't proved you have an actual spark, I suggest you do that.

The history strongly points towards it being an electrical fault, but it would be much easier to track down if you can find out whether the ecu is giving it fuel and sparks.

dilligaf76

Original Poster:

80 posts

69 months

Friday 7th February
quotequote all
I’m guess I could take a plug out and check it…

Feirny

2,762 posts

162 months

Friday 7th February
quotequote all
Mine did this, and after chasing it for a good few days it turned out to be the coolant temp sensor of all things!

dilligaf76

Original Poster:

80 posts

69 months

Friday 7th February
quotequote all
What the coolant sensor stopped it from starting?

stevemcs

9,444 posts

108 months

Friday 7th February
quotequote all
Surely it has to be related to something they have done ?

GreenV8S

30,857 posts

299 months

Friday 7th February
quotequote all
Feirny said:
Mine did this, and after chasing it for a good few days it turned out to be the coolant temp sensor of all things!
Many engines can be a pig to start without the correct enrichment.

That's why I suggest starting by investigating the basics, avoiding assumptions.

Feirny

2,762 posts

162 months

Friday 7th February
quotequote all
dilligaf76 said:
What the coolant sensor stopped it from starting?
Yep. It was a very bizarre one and random suggestion from a customer that prompted me to change it, I got the part through my work at £4 and it fired straight up first time and ran perfectly after.

Belle427

10,571 posts

248 months

Saturday 8th February
quotequote all
If the instruments were removed on some Vag stuff it does something with the anti theft system, i seem to remember having an issue on a Seat some years ago. I cant quite remember what i did, maybe try disconnecting the battery for 10 mins or even using a code reader to clear codes.

E-bmw

11,050 posts

167 months

Saturday 8th February
quotequote all
dilligaf76 said:
I friend of mine has got this car which was working perfectly fine until they decided to remove the dash and add aftermarket lights and switches by splicing into the wires.
Since putting everything back it won't start. It turns over but it seems there is no spark to the plugs.
What on earth could they have done to cause this?
My best initial suggestion would be to go back over the job with a fine tooth-comb and even better return it to the way it was initially.

If that works get them to take it to an auto-electrician next time they want additional lights.