PVf44 61 fuel pump
 

Hi,coming back from a run in the PV the car stuttered and came to a halt a«After a few attempts to re start I came to the conclusion that it was a fuel problem and had the car recovered to my home. I thought the quickest way to check was to lift the lid of the fuel bowls in the carbs and sure enough they were empty. I suspected a failed diaphragm so I removed the fuel pump and striped it down. The diaphragm was OK so I turned my attention to the check valves and as you can see in photo one appeared to be faulty. I have ordered a pump rebuild kit and intend to replace all the parts whilst the pump is off. My question is would the failed check valve alone cause the pump to stop supplying fuel to the carbs or should i be looking elsewhere.I strongly suspect the failed check valve but would like some confirmation. On previous occasions at high revs the car has stuttered but regained after I lift off,i had put this down to vapor lock in the hot climate.

arcturus;

Failed FuPu non-return valves can fail individually and intermittently, resulting in strange symptoms, before they fail completely, but I think it would be good to start with a careful inspection (to assure nothing which the rebuild kit doesn't replace is damaged) and to rebuild it...I expect you will find it will then once again do its job well...

Cheers

Before I re fit the overhauled pump,two questions. First,why two gaskets between pump and block and secondly,the rubber "washer" included in the repair kit,nothing like this came off the pump.Any idea as to its purpose?

Gaskets go one each side of the paxolin spacer. Rubber washer may go on the diaphragm pushrod and is easy to damage when fitting.

Bummer,after all this I find that it's not the pump after all,there is a fuel blockage somewhere in the system.I am going to try to find some sort of pressure pump and try blowing back down the fuel pipe. Is there a strainer in the tank? Any advice most welcome.

Arcturus;

May I remind you that you may forgotten the first rule of troubleshooting: Check the simple things first!

Tip for reassembly: The FuPu Spacer is brittle (I thought it was of Bakelite, but apparently Derek has better info on this), so tighten the FuPu Bolts evenly, and finally less than if you were tightening upon a stack of metal! I can't shed any light on what the rubber part might be for either...

There is no strainer in the Tank that I am aware of, but a Pick-up Tube to the bottom of Tank.

Before using "some sort of pressure pump", I suggest you simply connect a short piece of hose onto the Tank line and blow the blockage back into the Tank (remove Tank Cap to allow this!)...often, such a blockage consists of many rust particles, so this may be enough...alternately, you could a little pressure from a can of carb cleaner snoozle into the hose...

One a cleared path has once again been established between Pump and Tank (and you know there is some sort of debris in the Tank), I suggest you plumb a fuel injection fuel filter (so large, with a large filter surface area) in, immediately at the Tank (this my require cutting the hardline to add it in), and have a second FuFi handy for quick changeover when Fufi is blocked (these can be back-flush to remove and allow inspection of debris, and can be reused or replaced)...this will allow you to capture the debris...eventually, you will prevail.

Good Luck!

Hello again. Steps so far.disconnected fuel line to carb and as some fuel came out of pipe (raised the end of pipe an plugged it to stop fuel gravity flowing) I guess that the fuel that came out of the fuel line was only the residue.Pump reconditioned and refitted.Fuel line reconnected and manually primed but nothing came through.Turned motor a few times but still nothing. disconnected fuel line and tried blowing through back to tank,no result.Tomorrow I will try some more back pressure to tank. If still not clear I will loosen the pipe connection to tank and see if fuel dribbles out, if it dribbles out then I will check the fuel line. if no dribble I will siphon empty the tank and disconnect the pipe and try clearing any blockage in tank. I have a nasty feeling that this going to be an expensive job.

Looking at all the parts book illustrations etc it seems that the pick up pipe in the tank enters near the top of the front face of the tank and then has an internal bend which locates the pick up at or near the bottom of the tank. My question is,does the internal pick up pipe have a sharp right angle bend or is a curve? I may need to poke a wire or something to clear out any debris.

If it's like the Amazon tank, the pick up pipe has a sharp bend.
Can you remove the sender unit and look inside the tank?

I think that I have sorted it. Heath Robinson set up with vac blowing to clear fuel line. I made a balls up with the check valve fitting as you can see in photo. two fitted the same way where as the inlet and out are fitted differently. hard to find clear assembly details on internet search
Problem uploading pic's will try later

No joy with photos.