My son has a 1999 Polo 1.0ltr. It has an intermitant fault where the engine cuts out and wont start again.
It failed on him again on Friday night. When I went to it on Saturday morning it started straight away, this has happened a few times now.
Has anyone got any experience of this? I have done a bit of googling and relay 167 comes up a bit as a fault and also the Hall trigger assembly in the distributor, Has anyone had experience of this type of fault.

Thanks.
Steve.

Not sure about the polo, but my wife's golf Mk3 drove fine when we bought it, drove it home about 80 miles, (it had been sat for a few months so would benefit from a good run) stopped for fuel on the way, started and ran fine. Got home, wanted to let it run for a while just to check it didn't overheat or anything, ran for about 5 mins then stopped and wouldn't start again, wouldn't even fire.

Turns out it was the coil pack, common fault, changed that and it fired up straight away and always does now

HTH

Hi Steve,
again not polo. I had a Mk2 Golf Gti that did something similar. Turns out it was the fuel filter.

Cheers,
Donny

I had a similar problem with a chafed wire to the crank position sensor - just stripped and crimped the wires to fix it (once I'd spent ages finding out thats what it was of course).
Also had a similar problem problem when I last had thecar serviced at a garage - they forgot to do up the battery clamp.

Regards
Hugh

Main relay is a distinct possibility --- not unusually for the soldered joints on the relay circuit to fail on older cars.
Crank/dizzie sensor or its associated wiring would also give very similar symptoms as would a coil pack.

Although a diagnostic that covers VW can be bought for only £30 or so I suspect with this type of fault a scan is unlikely to return useful fault codes. It would really be a case of basic fault finding when the fault is presentie probing with a DMM checking if the injectors and coil are getting pulsed, then check the fuel pump is pressuring the fuel injectors.

What do you mean by "wont start"?

Does it crank but not fire?

I had a 1.6 polo of a similar shape, it refused to start intermittantly because the imobiliser transponder system was not working properly... so the car assumed that the key was not present sometimes....
(aa guy said at the time it was something to do with the transuducer loop in the column)

A very very frustating problem...car would crank and fire a few times and then die...

I now have a slightly 2001 GTI (similar chassis but very different electronics) which refused to start when the engine temp sensor failed... the "eronious temp readings caused the engine to flood on crank and then not start"

It does crank over fine. It actually croaked as he pulled away from a junction and another time he was sat at some lights and had been idling normally for a minute or two and it just stopped.
I tried my Vag Com on it and there were no stored faults, but as said there would probably not be as it wont see a problem with something like a relay or a coil switching off. The lad said heard the fuel pump giving its short burst before cranking so I am leaning towards an ignition/injector trigger fault.

Thanks for your replies guys.
Steve.

[Edited on 31/1/11 by stevec]

had that issue with my old 106, it cut out while driving then wouldn't restart for a few min, then evenualy wouldn't restart at all
it was the ignition module on the dizzy (I think its a HAL effect one, but unlike yours its a stand-alone setup with no ECU) cost £30 to fix, so not too bad

apparently it was a very common fault on the old pug's



[Edited on 31/1/2011 by mcerd1]

The square coil can cause this when they get a bit hot, very common problem. Hard to tell without knowing what isn't working (sparks or fuel).

Thanks chaps, I have ordered a new dizzy and a new coilpack and amplifier and a new main relay.
It will be easier than having my son phoning every 5 mins to drag him home "Hopefully"

Thanks again.
Steve.