7 replies to this topic

[Chris Donaldson]

My Dad has purchased http://minispares.co...|Back to search fuel cap to go on his MPI. Now he had got it he has been told it is a vented cap and that the MPI requires non vented for a sealed system. Is this the case? And if so I've not seen any caps for sale that specify either vented or non vented so how would I know what's suitable?

[Chris Donaldson]

Just found an old post on here where people have said that it is a non vented type on an MPI but in that thread 2 people say that they are running vented caps on their cars. Would this cause any damage/reduction on fuel flow etc or is it more of a "we recommend" rather than a "must" run a non vented fuel cap?

[minidaves]

should be a non vented cap on a mpi, vented cap was really for van pick up and estate as tank had no breather 

[Chris Donaldson]

So will using a vented cap cause any issues?

[M111OWW]

I can't really see a problem using a vented cap..
It must be for emissions reasons, the tank set up is the same as my Spi and it vents through the purge valve and charcoal canister under passengers wing.
Using a vented cap would allow fuel vapours out to atmosphere and not burned through intake breather pipe work..

I'm considering a vented cap because my in/out tank vent valve isn't working properly and causing a vacuum in the tank as fuel is used..

Hope that helps..

[Ethel]

It should work fine, but should be an mot failure, not that it's likely to be spotted.

[Chris Donaldson]

Thanks!

[Alpenflitzer]

Does anybody know how to make out of a vented cap a "non-vented cap" ?