Punto stalling - heather davies
My 1997 Punto (86,000m no short journeys) stops once it has done 7m from cold. It will not restart for 15-20 mins and will then do 2m and stop again requiring further prolonged rest. It then repeats the performance every 2m. Fiat are mystified. Help! The car is a cracker otherwise and I want to keep it.

PS a hot date for the problem-solver
Re: Punto stalling - steve paterson
Dear Heather, with this sort of intermittent fault it's always best to have a mechanic with you when the fault occurs. I can then make some basic checks for the presence of fuel / spark etc.
Love, Steve.
Fuel Vapourisation? - Guy Lacey
Is this something to do with fuel vapourisation giving a failure in fuel injection?

I know this happens on carb fed motors but not this (if it is injection?)
Re: Fuel Vapourisation? - John Slaughter
Blocked fuel tank breather pipe?

Regards

John
Re: Fuel Vapourisation? - Ashley
Heather,

Take the car for a run and when it cuts out remove the fuel filler cap. Listen for a whooshing sound, and if it occurs then the tank breather is blocked and air is rushing in to replace the vacuum.

Also, what petrol are you using ? If you use supermarket fuel try using a well known brand and see if that helps. What about the fuel pump relay switch ? I've read about hairline cracks in soldered joints before now.

Good luck,

Ash.
Re: Fuel Vapourisation? - budu
A bit off the subject maybe, but my Mgf 1.8i always gave a mighty intake of breath when I took the petrol cap off. This did not stop me on one occasion from driving fast on a deserted French motorway for about two hours without once changing down.Ashley wrote:
>
> Heather,
>
> Take the car for a run and when it cuts out remove the fuel
> filler cap. Listen for a whooshing sound, and if it occurs
> then the tank breather is blocked and air is rushing in to
> replace the vacuum.
>
> Also, what petrol are you using ? If you use supermarket fuel
> try using a well known brand and see if that helps. What
> about the fuel pump relay switch ? I've read about hairline
> cracks in soldered joints before now.
>
> Good luck,
>
> Ash.
Some electrical thoughts. - David Woollard
Heather,

Not sure of the ignition system on this Punto but had exactly the same problem on a VW a few years ago. It was the ign coil breaking down when hot. Made worse on the VW because the coil sits above/touching one of the heater hoses.

Boy did it do my head in for a while'till it happened in the workshop after an extended fast idle test period. Then I drove it up the road with my electronic gear connected under the bonnet and watched the fault show on the meter as it died. A new coil for £20 and it was fine.

I also had a similar problem with our own Fiat Uno a few years ago. This would get up to the local town chip shop on a Friday night (5 miles) and then not re-start to come home. That was a faulty ignition trigger unit in the distributor breaking down when hot. About £40 to change that.

If this does prove to be near enough for even a lukewarm date I may have to sadly turn it down. Have mentioned to the forum members before many of my customers are single thirty-something girls. Strict rule to keep my life on track....never let them take you up the road to listen for "that little squeak"!

David
Re: Some electrical thoughts. - Tom Shaw
Had the same problem on a couple of cars years ago, and I'll agree with David about the coil being a likely culprit. It was on both the occasions I refer to.

Heres where I probably show my technical ignorance, but I did not think any modern cars were fitted with a coil?
Coils. - David Woollard
Tom,

There has to be a device to produce the spark, it may not be in the place you expect or look like the old coils but effectively it's a coil.

Don't look after any Puntos at the moment (mostly Citreon, mostly diesel here) but my trade data book gives the coil winding resistance figures for the Punto.

Collectively I think we might be getting there, wonder how many Heather can fit in the Punto for our fish and chip supper (once repaired)?

David
Voice of reason - David Lacey
I'm not too sure but I think this car has a rather elaborate ignition unit situated on the RH inner wing. This looks very similar to other units we have changed for similar problems. I'm sure it contains the 'not so reliable' ignition amplifier unit. These do seem to affected by underbonnet heat.

It would be worth removing the fuel cap and perhaps replacing it with a £1.99 temporary cap and take the car for a drive and see what happens. This would rule out any fuel system pressure/vacuum problems.

But, it could still be the coil - some Rover models have the coil bolted onto the back of the engine. These can fail at certain temperatures and when left to cool are fine.

Rgds

David
Re: Fuel Vapourisation? - Michael
Ashley, I thought modern cars, with fuel injection et al, had sealed systems. In fact, as I write, I remember reading a Technical Service Bulletin from VW about a known problem on golfs (misfiring etc) where the fault is an incorrectly fitted petrol cap. If it is not screwed on tight, air enters the tank and causes problems. Your advice is sound for older cars, without fuel injection, but I think modern cars have different needs. Not much help for Heather, other than she will here a whooshing sound but it may be normal. Our primera whooshes every time we take the cap off.

The last time I had a problem like the one described turned out to be a faulty ignition coil that would stop working when hot but was ok cold. Took weeks to find.
Re: Fuel Vapourisation? - Ashley
Ok, ok, i was just trying as many different ideas i could think of to try and win the hot date guys !

Looks like i'll lose out to Dave then.

Ash. ( disappointed )
Re: Voice of reason - Michael
David, see my reply regarding the VW tech service bulletin above. I know it's a different make but replacing the fuel filler cap with a vented one could cause problems....