lift pump wearing out, leaking air?

[GREASE FIRE]

hello,
has anyone had problems with the stock lift pump drawing air into the system? mine is only a few years old but has run lots of wvo/wmo so i wonder if that could cause it to wear out sooner than normal.
anyway, after replacing all hoses and clamps and tightening them very well, i still have this problem where my truck starts losing rmps going down the road and eventually stalls. as this is happening, i see lots of white smoke coming out the exhaust pipe.
as soon as it stalls, however, it will start right up immediately and drive as normal! sometimes for weeks, or at least a few hours before the problem happens again.

just wondering if the pump could suck air in somewhere other than the inlet (where the hose clamp is very tight) due to a small leak in the diaphragm and/or metal casing. has anyone had this problem?
thanks!
paul

 

[79jasper]

How many miles are on the injector pump and injectors?

 

[9779scott]

If it is getting small amounts of air in the system it will rev up not loose RPM's. I had a problem where i had a line that had a small crack in it and it would open up just alittle when going around a right corner and the truck would feel like like just hit the nitro button and break the tires loose on dry pavement. My thought would be some crap in the tank partially cloging the line then when it dies it comes off the end of the pick up tube then fire right back up. I had this problem a few years ago. Dropped the tank and there was a piece of foil from a fuel additive bottle.

 

[icanfixall]

Its not likely the diaphram sel is leaking but that rubber hose feeding fuel to the pump can wear out too. Follow the hard line from the lift pump to the filter head. Where it goes into the filter head that brass fitting has an olive gasket in it. That size is 3/8. any injection repair shop will have those and even napa sels an installation kit for the injection pumps that has this gasket. So these are a couple of possible leaks that suck in air but wont leak out fuel..

 

[bagpiperjosh]

sounds similar to the problem i'm having. it will stall under heavy acceleration sometimes. but i usually have to crank my engine for about 10 seconds or so for it to start again. let me know what you find out