UK-POLOS.NET - THE VW Polo Forum

Hi everyone.
My name's John. I've just registered here and this is my first post.
I hope you don't mind my asking for help.
I've got a Polo from 2003-4 which refuses to start.
The engine turns, there's fuel, there are no error codes.
I've taken it to the VW garage. They've looked at injectors, compression, exhaust, and checked with their software but no error codes.
The guy says the next step would be to change the ECU (1,500euros more or less), but without any guarantee that the problem would be fixed.
He's totally upfront that they can't find the problem, but that changing the ECU would be the next step.

Does anyone here have any ideas as to what could be wrong?

The only vaguely relevant thing is that it cut out about 50kms before it refused to start again. On that occasion, the engine was idling and just stopped. I though at the time it was unusual. It started again with first turn of the key, but then a couple of days later just refused to start at all.

Apart from that... Nothing.
I've had it since 2007 and it's been 100% reliable.

I like the little car very much, but it's not worth much, esp as I live in Spain and there's no AC.
Sadly, it's looking as though it's the end of the road.

Any ideas would be very much appreciated.
John

And one more thing...

When the car's been standing and I try and start it, the engine catches momentarily as though it wants to start.
I mean it fires a few times, then just turns.

This only happens the first time I try and start after a while.
The rest of the time, it just turns and turns.

Welcome to the forum

From reading what you've said you didn't mention if anything to do with the ignition was checked/tested.
These cars are known for having coil packs that fail but it's usually only 1 that will die and give you a check engine light and an error code so I doubt all 3 have died at once but maybe it's worth a look as you never know.

You also may as well try new spark plugs as they aren't that expensive just to eliminate them.

If there's also something wrong with the timing like the chain jumped, this could cause a crank no-start but you mention that the compression was checked. If the timing was out the compression would be low and or you would have had your valves meet you pistons causing catastrophic engine failure. However, you mention it sometimes fires but then dies and continues to just crank. Not sure if it would throw an error code when just cranking but maybe a crankshaft or camshaft positioning sensor has failed making the ECU not know the timing of the engine but I'm not 100% on that hopefully someone who knows a bit more can jump in.

Bepis, thanks for the reply.

One of the coils died a couple of years ago and I changed all of them. So, really unlikely to be them.
I also changed plugs about the same time so again unlikely.

Before I took it to the VW garage, I changed the camshaft position sensor. Clutching at straws, really, but it was easy to get at and cheap. I'd also plugged in my reader and got no codes.

The VW guy checked the compression, and the local mechanic looked at the chain about 5k kilometres ago. All ok.

I'm *really* reluctant to scrap it without knowing what the problem is.

Hello baobab. Please tell me where is located the camshaft position sensor. I see that you changed it and I didn't find it, I don't know where is located exactly this sensor. Thank you.

What about fuel supply? has anybody’s checked it’s getting fuel, and is it good fuel ie not mixed or contaminated with diesel.

You seem to have checked all the electrical side and compression all it needs now is fuel ?

Thread a bit old now but no harm in suggestion....any time you get problems like that i would suggest checking out the fuel pump, lift up the rear seat squab, the fuel pump hides under a plastic cover, remove this, then unclip and remove the wiring harness from the fuel pump, there are 4 terminals on the pump, two narrow ones for the fuel pump sender and two wider ones for the pump motor, check the resistance with a multi meter for a few ohms, if its open circuit, fuel pump is kaput.