[urq] Fuel Pump surge - still having problems

[cody at 5000tq.com]

Quoting Ben Swann <benswann at verizon.net>:

> Cody,
>
> Did not really want to get into the trouble-shooting aspect all over  
>  again, but to
> answer your question below, the tank is neither vacuum nor pressure.  
>   There is basically
> an open line that was carbon can and pressure remains even with   
> atmospheric.  I have
> checked and rechecked for vacuum in tank along with restrictions, etc.

Understood, I just wanted to be certain that you were certain ;-).

>
> The system is similar to M90 and is in fact presently using the same  
>  pump Model 90 uses
> - idoes not make much difference, as Wallbro worked pretty much the   
> same..  If I recall
> the model 90 setup is just more conducive to flow whereas the UrQ   
> seems to have a number
> of bends to go through.  I may be able to reduce the intake pipe   
> complexity, but in the
> end, don't foresee resolving this problem without some sort of   
> dual-pump/surge tank or
> cutting the tank open and installing an internal pump.


Instead of going to an internal pump you could simply drain the tank,  
purge it with some inert gas, and install a larger outlet on the  
bottom - just weld on a bit of like 1" tubing, then use a 1" use into  
a reducer right at the pump. You'd DEFINATELY want to run a pre-filter  
as you'd be deleting the in-tank sock, but it would fix any problems  
with the gravity fuel delivery.

>
> Interesting point about the voltage reduction - presently the pump   
> is jumpered on all
> the time and full current available through relay.  That may be   
> contributing factor, but
> don't understand why if pump is on continuously even with fuel pump   
> relay - unless the
> engine cuts.  I don't think going down this path is working toward a fix.


Agreed, just tossing out ideas.


-Cody