Breakdown!

[f40fanatic]

i was on the way to the beach the other day, and i broke down half way, the fuel filter was empty and it wasnt pumping fuel, i blew through all the fuel lines and did gst it running, but the fuel filter still doesent fill up properly but it is taking fuel into the engine. Does anyone know whats wrong??

[Hazey-n-Marc]

could be a leaky fuel pipe, they tend to draw in air when they first go, then they start spraying petrol about a bit later. Or could be fuel pump.
Also check there is no movement where the fuel lines attach to filters, pump and carb, just give 'em a little twist.
 
Marc

[f40fanatic]

i can twist the pipe leading from the pump to the tank, the air breather pipe, its on tightly but the jubilee clip isnt great, its possible to twist but not very easily..

[Hazey-n-Marc]

Jubilee clips do not close round, so are generally not great for fuel lines. Fuel line clips are very cheap (think I paid 25p each from parts place in town), and will give a more even seal.
If you have no loose connections or perished lines a fuel pump is cheap and held in with only 2 bolts, distributor has to be lifted as well, make sure you mark it's position before moving it (I wish I did!!) and you should be fine.
 It may take a while to pull fuel back through once you have done this, another car with jump leads, or suck it through if you can stand the taste of petrol for a day or two, should do the trick.

[thepuddlejumper]

The fuel pump is next to the alternator on the other side of the engine from the distributor.  It is held on with 2 bolts, there is a rod which is moved by the cam shaft which pushes onto the diaphram in the fuel pump this cold be worn resulting in not enough fuel getting through a common problem.  To remove the fuel pump remove the supply pipe from the tank and the delivery pipe to the carb then undo the 2 bolts and it should lift off.  Replacement is the reverse, but check the length of the rod, someone on this forum will know the correct length unfortunatly I can't remember but will have a look for it.  Hope you get it running soon to enjoy all that sunny weather don South, it's warm wet and misserable here in Bonny Scotland and I'm just going out to replace the carb on my 126.  Happy days.

Ralph

[Hazey-n-Marc]

Are you talking about air cooled, or a BIS? Think puddle jumper is talking aircooled (never worked on one myself), I am talking BIS, Watercooled.
Marc

[Rusty's Uncle]

I think you are right as Ralph is an air cooler man like myself which is why my bit about sumps would have been a bit confusing . 
If the pipe joints are half decent then you have got to suspect the Fuel Pump. My 500 refused to start twice this year until it had cooled down for about 30 mins after a good thrashing. It was hardly pumping any petrol. As the car has done over 100,000 miles I suspected that the push rod may have been worn. The pump was one of the sealed for life types so not original. I removed the pump and rod and the rod looked fine as it still had the chamfered edges at each end. After much searching I found some info in the factory workshop manual. On dwell the rod should extend 1 to 1.5 mms out from the outer gasket and the throw on the cam is 2.4 mms. Did some measuring and it was all fine so fitted a new pump as I guess the old one was packing up, made worse by the differential expansion of the rod and crankcase.

[f40fanatic]

Ive taken the pump off countless times, it is pumping ok, but might be suspecting that it is letting fuel sink back through into the tank and draining out of the filter.