Douglas Brown

I am noticing air bubbles appearing in the clear fuel filter while running. Filter is positioned after fuel regulator (set for 6.5 > 7 lbs)and before carb.

Also when motor is off, fuel drains back toward pump, causing motor to crank longer during cold starts, than needed to refuel carb. When hot fuel drains back toward pump but starts right up.

I do not recall this being a problem with vehicles of these years. A pump should hold pressure? right? Or is there a check valve required to do this?

MelWff

The pump should have a check valve. What type of carburetors, there should be fuel in the float bowl ?

Douglas Brown

Hello Mel...I have a Edelbrock 1400....I do not think there is a check valve, other wise the fuel would not run back to the pump from the carb.

I may have to buy another fuel pump, It's the air being pumped into the gas line that's got me confused. If I have air going in then I fuel coming out. You would think.
If before the pump you would suck air not fuel...?????
From pump to carb pump in bubbles????

terry82

for safety I would get rid of that clear fuel filter.

Douglas Brown

Yes..your right.....but for now while checking the system. ..I would never had known about the air bubbles being pumped into the line were it not for the clear filter.

MelWff

the check valve has failed

Mike Ward

The clear filters always have some air in them. Makes no difference but get rid of it, the pressure regulator and any rubber fuel lines anyway.

Douglas Brown

I ordered a new pump, and lines from the pump.

Douglas Brown

The other fuel pump was new, but had a 7-9 psi, hence the regulator. The clear filter was what was recommended by the parts person from his computer. I should have know better.

As far as there being air I the clear filter, yes that is to be expected, it was the air bubbles coming from the regulator / pump side of the lines that got my attention. and if there is a check valve that failed which allowed the fuel to drain back that may explain the bubbles.

new pump is a 6psi from Edelbrock. no regulator needed to operate with the Edelbrock 1400 carb. new lines from pump to carb and filter coming...

Thanks for input & help from all

DB

Douglas Brown

New pump arrived, fuel lines steel as well....metal case filter....
New installed, new line at carb installed, Fuel filter had to placed down under where the 1982 filter goes, no room on top with all the smog tubes and pump. The stock fuel line though is not going to work with this new pump, no room for stock fittings, unless I cut and bend it to fit and fight with it. I'll look into a steel braided line later. Right now I just want to get the different systems checked out and working...Still have to get the A/C system charged.

Thanks for the help
DB