Lotus Elan and Lotus Elan Plus 2 Forums

I have a new Facet Posi Flow 4-7 psi pump with fuel filter (which is clean) mounted prior to pump , regulator after pump.

* Note the fuel filter is a canister style with a replaceable paper element rated at filtering down to 10 microns.

The pump works 90% of the time, though concern point is at times , the pump knocks all of a sudden then pressure drops.

If I remove the rubber fuel line from carbs or pump for a second and reinstall , then turn on pump it returns to the low operating noise (no more knocking) and pressure returns to 3 psi.

I’m thinking the tank is getting too much vacuum and the Enots quick fill fuel cap may need a larger home drilled in the brass plate? Or that the fuel filter is not coarse enough the current paper element is too fine ?

What’s your experience with this ?

Thxs
John

1963Turnerjohn wrote:I’m thinking the tank is getting too much vacuum and the Enots quick fill fuel cap may need a larger home drilled in the brass plate?

on that specific point, can you try with the tank cap opened to see if the problem still occurs?

No not easily - as the facet pump acts up indiscriminately, most times while on the road - so cant leave cap popped open as a running trst.

If it occurs in the driveway, yes I will then try to pop open the filler cap.

Yes, I'd agree, does soumd like a vacuum / cap not breathing properly issue.

I’ve found the culprit!

The canister filter housing became a slight bit loose, thus I saw a slight coat of fuel residue film on the housing and the decal was starting to peel off.

This was only in the car 120 miles - so most likely the canister bolt vibrated loose enough to get a air/fuel leak.

I’ve fit a inline Facet 74 micron filter and all is as it should be!

If you use a canister fuel filter, keep an eye on those canister filter housing bolts fellas!