[urq] Fuel Pump surge - still having problems

Cody Forbes cody at 5000tq.com
Wed Apr 16 20:47:29 PDT 2008

Louis-Alain Richard wrote:
> Ben,
> Maybe you can install a restriction on the return hose so the all the
> circuit will be pressurized from the pump to the restriction but with
> less flow overall ?

You mean like the fuel pressure regulator? ;-) The only way to really 
decrease flow without incresing pressure in this case is reduce the voltage 
to the pump. BTW Ben.... you could reduce the voltage to the pump to slow it 
down and stop the caviation, maybe install a switch to bypass the voltage 
reduction circuit in any case you need full volume. For a matter of 
consistency I'd recomend a voltage regulating circuit instead of just a 
resistance circuit.

How simmilar is a 80 or 90 fuel system (in the tank to pump area)? I know 
they are gravity feed to an external pump like the urQ, and I know that Jim 
Green in his 1989 90 used his stock pump and such with both his 10v and 20v 
setups and power levels from QLCC-ish to well over 500hp at the wheels. At a 
certain point he added a second stock 90 pump in paralel to add volume.

Ben are you certain that your tank isn't being drawn to a vacuum? Maybe just 
for a quick test try with the fuel cap removed to just completely eliminate 
that possibility.

-Cody Forbes
'87 5ktq - Fast.
'87 5ktq QLCC'd plus some
'86 5ktqCD
'86 5k
'86 5k 

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