I want to fit a fuel pressure gauge in the dashboard. I already have an oil pessure gauge, so i only got a sender and will use a rocker switch to alternate the readings.

Sender is an 1/8" NPT type




My motor is a 1.2 75ps mpi (Punto75), so it uses the 4 injector rail, with the fuel hose using a threaded fitting on the end.

I found this on ebay

http://cgi.ebay.co.uk/8-AN8-Male-Female-Union-1-8-NPT-Side-Port-/150606505649?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2310d8e6b1



that i think simplifies the connection. It is an An -8 male to female, with 1/8 NPT side port. Is this the correct female thread for the injection rail?

This looks very much like a JIC 37 degree flare hydraulic fitting. AN-8 is 3/4" x 16TPI, which being a hydraulic industry rather than automotive standard, I don't think will be anything near. I'm ready to stand corrected though.

JIC is the industry variant of the AN (army navy) fitting, At least that is what Wiki says. They state them as intercheangable. AN is also 37 degrees flared.

[ame="http://en.wikipedia.org/wiki/AN_thread"]AN thread - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:ANfitting.jpg" class="image"><img alt="" src="http://upload.wikimedia.org/wikipedia/en/thumb/7/71/ANfitting.jpg/220px-ANfitting.jpg"@@AMEPARAM@@en/thumb/7/71/ANfitting.jpg/220px-ANfitting.jpg[/ame]

You say that the injector rail has a JIC fitting?

I meant to write that JIC is unlikely to be a current-day European automotive standard - I would be gobsmacked if the fuel rail on a Fiat had anything other than a metric thread.

I agree with The Professor. AN/JIC are very old US standards based on Imperial measurements. They might pop up on some older US cars, but nothing European or Japanese and probably nothing modern US either...

So, i'd better dissasemble the rail and take it to the machinist. Metric thread sounds reasonable enough for a european car...

You can get adapters which are 1/9NPT to metric, including T-fittings etc. M10 is quite widely used (on VAG cars). I am not so familar with FIAT though.