fuel line check valve - Ford Forums

77xcgs · 04-24-2007, 14:58

hi,anyone heard of a one way check valve being fitted between the fuel pump and the carb to stop the fuel leaking back when the car sits for a while?my xc 302 is hard starting after sitting for a week,but is ok if it only sits for a couple of days.any advice?

fordboy98 · 04-25-2007, 01:14

The inlet valve to the fuel pump actually functions as a check valve, by preventing reverse flow of the fuel when the pump pumps. The fuel lines should also stay charged with fuel between starts if the pump is OK. If you are leaving the car for a week between starts, your problem is much more likely to simply be evaporation of the fuel from the carby bowl. Especially true for a V8 where the carby is sitting over the hot motor. (With a six, its out to the side more and does run a little cooler). You just may need to crank it that bit longer to refill the bowl before she'll fire.

77xcgs · 04-25-2007, 02:05

hey thanks mate,i was wondering about evapouration,but it takes heaps of cranking to start it.ive replaced the fuel pump,plugs, leads,set the points and timing.once she starts its perfect.shes good for a couple of days and thats with a cold engine,so thought it wouldnt evapourate not being started?any other suggestions would be much appreciated.

fordboy98 · 04-26-2007, 23:31

Yep, it will evaporate whilst the car is standing. And of course if you've driven it beforehand, the valley area will be at least warm, so that will keep the fuel in the carby warm and encourage evaporation. Remember too that while you are driving cool fuel is being pumped up to the carby from the tank, so evaporation won't be an issue. Vapour locking is something else again, but that's not what you are dealing with here. The other possibility is that youy have a leak or a weep from the carby bowl (like a jet holder or something) that allows fuel to actually leak. This only becomes a problem when the vehicle is left to stand for a while - like a day or so in your case.

Out of interest, somre cars that run on gas (eg Hxxxxxen V8's) actually have to have the soldered brass float in the carby replaced with one made of a plastic composite. Reason? With the LPG cars the carby body gets hot enough to melt solder. Exit one float.

77xcgs · 04-27-2007, 00:36

hey fordboy,thanks for the help.its all becoming alot clearer.im hoping its the fuel leaking down the carb,at least ill be able to do something about it.cheers