Author Topic: New Fuel Pump and car now dies after idle for a bit  (Read 1733 times)

Offline baxternick

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New Fuel Pump and car now dies after idle for a bit
« on: November 27, 2016, 08:46:02 AM »
I have a Cadillac 500 with a quadrajet installed in my 54 Chevy.  The car ran perfectly for the most part.  The only issue was it would run out of fuel above 4300 rpm.  I already put in a new tank and 8an lines.  So next I just installed a RobbMC performance 1100 HP pump and a Holley regulator.  The regulator is currently set to 6psi.  When I first start the car from cold it runs great while choke is engaged.  Once I drive it around a few minutes the car falls on its face when braking or when sitting at a light even in neutral.  My AFR drops to 10.8 and lower when this is happening.  The new pump and regulator lack a return line that I had with my factory pump. I am wondering if the lack of return line is causing this?  I was also thinking the fuel pressure is to much at 6?  My final guess was Float Level was to high.  It is set to 1/4".  The carb currently has 77 Jets, 53M Needles, J Hanger, CE Rods, and a .145 Needle seat. The fuel pump upgrade cured my fuel starvation at WOT, but seemed to cause this issue now. Thanks for any input in guys!

Offline 77cruiser

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Re: New Fuel Pump and car now dies after idle for a bit
« Reply #1 on: November 27, 2016, 02:19:05 PM »
I'm thinking you might be right on the edge with 6 psi. & a .145 seat. Does the pressure creep up while driving.
Jim

Offline Cliff Ruggles

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Re: New Fuel Pump and car now dies after idle for a bit
« Reply #2 on: November 30, 2016, 05:38:28 AM »
I like to see a return line with any sort of mechanical or electric high capacity pump.  They can and will cause issues without one. 

It's one of those things that you will get a lot of opinions on, my experience prefers a return line set-up.....Cliff