Intermittent poor starting - Polo 6r 1.4 16v

[thewifespolo]

Hi All,

We are experiencing an intermittent starting problem with our Polo. Car is a 2009 Polo 6r 1.4 16v. Most of the time it starts first time but occasionally the car fails to start. Dash lights up as expected, engine turns over but the car refuses to start. I have checked the battery and it is fully charged. If we persist trying to start, say for 4 or 5 goes, it eventually burst into life. It looks like a spark issue, but i'd like to hear if anyone out there has experienced the problem, and whether there is a known fault that is easily sorted.

Thanks in advance for any advice

[Robby71]

I had this issue on a 2009 Seat Ibiza 1.4 which i think is the same engine?
The problem seemed to be common on the Seat forums and the solution was to take it to the dealers for a software update - i traded the car in before i found this out

[thewifespolo]

Thanks for the response. I've got a hunch it may be a defective fuel pump relay. I can't locate any relays tho. Does anyone know where they are in a 6r Polo?

[RUM4MO]

Can you confirm if this happens any time, or only for a cold start or only for a hot start?

Maybe get onto the SEAT forum and see if you get more answers there - and where the fuel pump relay is located as I'd agree that it should be the starting point. ( www.seatcupra.net )

[ciclo]

Why do you think that the fault can be due to the fuel pump relay?
It can also be due to:
Throttle valve (cleaning).
Ignition coils (replace).
Spark plugs.
etc...

It is best to search for faults with a diagnostic tool. (e.g VCDS)

----



Relay carrier, from November 2009

1 - Low heat output relay -J359- (53)
2 - High heat output relay -J360- (100)
3 - Terminal 30 voltage supply relay -J317- (643)
3 - Current supply relay for Simos control unit -J363- (429)

l Models with engine code CGPA only
l Up to November 2010

4 - Dipped beam relay -J331- (449)

l Position left

4 - Fuel supply relay -J643- (404)

l Position right
l Models with a petrol engine only

4 - Additional coolant pump relay -J496-

l Position right
l Models with engine code CBZB only
l To May 2010

4 - Fuel supply relay -J643- (449)

l Position right
l Models with diesel engines only

5 - Voltage stabiliser 2 -J570- (505) → Note
6 - Fuse holder D -SD-

l See fuse concept

7 - Fuel pump relay -J17- (449)

l Position right
l Models with a petrol engine only

8 - Fuse holder E -SE-

l See fuse concept

9 - Starter inhibitor relay -J207- (53)
10 - X-contact relief relay -J59- (100)
11 - Headlight washer system relay -J39- (53)
12 - Starter relay 1 -J906- (643) → Note
13 - Starter relay 2 -J907- (433) → Note
14 - Vacant
15 - Terminal 50 voltage supply relay -J682- (449) → Note

l Position left

15 - Heater element relay -J925- (404)

l Position right

A - Fuses in relay plate fuse holder -S3-

[RUM4MO]

ciclo, there have been quite a few cases where intermittent poor starting has been due to a defective fuel pump relay, well on the Ibiza forums. I have asked the question about when this starting problem occurs as there is another problem turning up with these engines but only usually only when the weather (temperature) is hot.

Considering the possible age and mileage of that car, I was thinking that it would be too "young" to have TB or COP or plug problems.

[ciclo]

Ok, thanks for the explanation RUM4MO, I need to learn more about these issues.

[RUM4MO]

Ok, thanks for the explanation RUM4MO, I need to learn more about these issues.

At least now the OP knows where the fuel pump relay is located, could be that you end up being closer to what is wrong with this car!

If the OP comes back and says it only happens when the outside temperature is higher, then there is another issue that seems to be causing that - all this not from experience but reading VAG forums!!

[ciclo]

With reading also experience is obtained, and even more if the results of the help received are published.
(I admit I'm addicted to the results in repairs or tests... )

[iichel]

(I admit I'm addicted to the results in repairs or tests... )

aren't we all?

[RUM4MO]

Yes, the new members that appear out of the mist, complete with a problem then ask a few questions - and disappear again without reporting back on if that problem was fixed or not - THAT IS A BIT ANNOYING!!

[thewifespolo]

Thanks for all your suggestions. I haven't got round to getting the fault codes checked - I have got VCDS lite but don't have a suitable cable yet. I did try with an ELM OBD2 cable that I use for my Alfa 159 but can't seem to get VCDS Lite to recognise it.
The car has been behaving itself well recently and we haven't had the issue for a little while now. There didn't appear to be any obvious link to what the outside temperature was when It did play up. I thought it may have been the fuel pump relay purely because it felt like it wasn't getting fuel. I had another quick look for the relays but still couldn't find them. It would be helpful if i could find them - at least then if the car does refuse to start again I could check that the relay is working ok.

[ciclo]

If you search in the same way (gannu_1 picture )... also remove side cover dash to see the relays ... also through the hole between the steering column and dashboard.

[RUM4MO]

Hummmm, I meant to add a posting to confirm why you had posted that "picture"!

Man ready for action, new BCM at the ready - now try to get yourself out from that position - ouch! (even worse if you have just discovered that you have some small stones on the car mats!!

Maybe I'm too old!

[ciclo]

Older men use ingenuity and knowledges. (I'll never be too old to do anything, my mind is like that of an older child )

I am able to remove the BCM in 5-10 seconds while I'm sitting in the driver's seat, including caps from BCM connectors, and with blindfolded ... you can be sure.
Also any relay reaching into the gap between the OBD2 port and BCM holder...