Holley 390 cfm woes

[SIVAllan]

I have a brand new Holley 390 cfm carb on my Alpine's 2.8 v6.

I hope someone proficient with carbs can solve its "riddle."

It's been a problem right out of the box.

Initially, the front needle jet was sticking so I replaced it.

(I've had the needle jet problem with several Holleys.)

Subsequently, the fuel line acts as if it is blocked - the electric fuel pump buzzes just fine to signal it's working but I can see in the glass fuel filter that gas isn't flowing.

The fuel filter is placed in the fuel line about 8 inches before the line attaches to the front bowl of the Holley.

Obviously without gas the 2.6 engine won't start.

However - if I unhook the gas line at the carb and turn the ignition switch - as expected gas flows out in a normal stream.

Reattach the line and the 2.6 then starts, idles and runs the car just fine - for a few minutes - and then it's back to step #1 - no fuel flows through the carb.

If anyone can point me in the right direction I'd be most grateful. Resolving a handful of such "minor" issues seems as if it has become more time consuming than installing the 2.6 lol.

Thanks in advance,

 

[260Alpine]

Allan, What pressure is you fuel pump? Holley's like 5-7 psi where the sock carb prefers 3-4psi. Location matters too. should be close to the bottom of fuel tank. It is more efficient to push fuel. I like a filter down by the pump also.

 

[SIVAllan]

Jim, thanks.

I'll have to check on the psi. I'd suspect it's too high though, if anything, just by eyeballing the flow.

The fuel pump is located near the gas tank, almost adjoining it. The S1 just has the one gas tank placed
on its side in the trunk floor.

I sorta like the fuel filter placed where I can see it, and see inside it. I've never had a problem with the
location on other Sunbeams.

I suspect an issue inside the carb. I'll check the pump's psi as a first step, and then fiddle with the needle valve some more.

My v8 Alpine put me down in the Idaho panhandle - due to Holley needle valve voodo. A new valve did the trick that
time but doesn't seem to be working now.

 

[sunalp]

Allan,
Sounds almost like your float is stuck so it won't allow gas in. My experience with electric fuel pumps
is that they will get gas to wherever you want it, sometime so much that it will flood the carb. I generally
use a fuel regulator for that purpose.

Check your float level. By the way, as far as fuel filters go, I have one before the pump, and another in line
to catch anything that might escape the first one.

Hope that helps!
Steve

 

[mr.vman]

That Holley carburetor has externally adjustable floats. The float level is adjusted by needle and seat on top of float chamber (s0. Using the lock nut to move the needle and seat assembly up or down. When done, lock in place with screw driver with top screw (gas can flow out during this). With an electric pump, no reason to have engine running to adjust floats, unless levels are above window. Adjust fuel levels to just below windows. The normal Holley problem is, needle sticks open, causes flooding. Do remove float chamber and check that float is not sticking. Preliminary float level; hold float bowl upside down, adjust needle seat assembly until float is about level. Hope this helps.
Steve V. Arizona