Technical Fuel tank breather

[Bogul]

Hi, I have a severe performance problem with my 96 Punto 1.1
The car pulls and jerks all the time. I've had the onboeard diagnostics checked and apparently they are fine.
However removal of the petrol cap reveals what I would class a abnormal amount of suction so I suspect the fuel tank breather is blocked, can anyone describe which is the breather and if the tank vacuum is normal, I don't think it is.

Sorry if this seems a stupid question but it's been going on now for over a year and it's driving me mad.

Thanks

Peter

 

[kebab]

modern cars do not have fuel tank breathers too comply with hydrocarbon emission regs, effectivly the tank is vented too a carbon filter which is inturn conected too the inlet manifold by a ecu controled valve.
also just because there are no errors in the onboard diagnostics does not mean all is well with the injection system.


uno 1.0ie RAAAWW!

 

[Bogul]

Ok Kebab, Thanks for the info but is the tank vacuum normal or is the problem elsewhere?

Peter

 

[kebab]

i dont know, they all hiss when you remove the filler cap but weather or not thats a vacum or positive pressure i just dont know.
regardless of that run your engine with the cap off, if it still plays up then you know thats not a problem.

uno 1.0ie RAAAWW!

 

[thefishdude]

sister had jerking problem.....dam that sounds wierd....anyway as i was saying my sister 1.1 had a jerking problem turns out just to be new set of plugs needed and al sorted after that. could also be coil pack.

2001 Punto sporting in sprint blue with matching Mr Bump air freshner all together now mmmmmmm

 

[no1sourlung]

I too had the same problem and it turned out to be the spark plugs. I had them changed and the problem stopped straightaway.