How do lift pumps die, do they just: slowly loose there go? just die? FLutter in and out?

Thanks

 

from what I have read on here it is both ways....

 

Mine just got weak. Never failed completely. Replaced with a new one, but now Holley blue and big line kit on the way.

 

mine did a little bit of both. it didnt gradually get weak, all the sudden one day the thing just started going TU. pressure was alot lower than normal, alarm was comming on for low perssure. at times it would be ok, then drop back down, it was erradic to say the least. roughly, it acted as if it got shot then flopped around for a couple weeks till i changed it. if you think its going, change it. it will save you the headaches of having to replace a VP at the same time.

 

I have had one get weaker over time, and one start acting erratic all of a sudden. It is a lot easier to diagnose a lift pump death with a gauge instead of just a low pressure light.

 

we caught ours the moment before the pump burnt up. what happens is in the housing is an impeller that is connected into the motor by a key and a bushing. the poor quality of the bushing comes into play when the fuel and time make it disintigrate. then the motor spins freely not pushing fuel so it burns up and give u a lack of fuel pressure.


note the empty circle where the bushing should be that connects it to the motor

 

I have two lift pumps and what really baffels me is that it will be fine for a while then when crusing at a constant speed the psi will start fluttering all over the place. However if i was to step on the skinny the fuel psi jumps right back to were it should be about 9,10,11 psi dependng on how hard i step on it.

The other thing that i have noticed is that if i trip the starter to get it to do the 30 sec run, after the truck has been running, it will not always do it. It will go erh erh erh like the fuel pump sounds then not kick into the 30 sec run.

Any ideas on any of this. I am planning on getting a walbro but i really cant shell out the coin right now. Thus im not driving very far till i get it figured out.

Thanks

 

The walbro is $110 on ebay, then all you need are fittings and hose.