Overloading Quadrajet
 

Last fall I began to have problems with fuel blowing out the carb. I assumed some dirt got into the works, so I took it apart and put in a new float, new gaskets and all the other parts that came in the kit. Placed the carb back on and within a moment it was doing it again. Several times in fact
I had already ordered a new Q-jet from SMI as the old one had formerly been on an old combination (455) (now a 467 Stroker) that has a flat spot in it that I couldn't seem too tune out.
Put the car away in the fall, and last week the new SMI carb came in. I uncovered the car today , hooked up the new carb and 30 seconds later gas was puking. Same issue.
So now I suspect the fuel pump. It is an Edlebrock mechanical 110G unit that has been on the car for 15 years. it only has a main line in and a line to the carb. No return line
I'm assuming the pump is putting out too much pressure but don't have a pressure gauge in the system to check it. I was wondering why all of a sudden, the pump would up the line pressure after performing flawlessly for years.
Before I toss it out I thought maybe some of you guys could help with a adding a new pump (no I don't want to go electric) . I was looking at a Carter from Rock Auto, but they are only 40G/Per minute

https://www.summitracing.com/search/...20-gph-454-lph

it does look like the 110G type pumps are still available if you'd like to get the same of what you already have. you may want to put an inline fuel presure gauge to validate what's going on.

The eddy pumps can be rebuilt.


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might give Sean a call as he built your carb?He will probably suggest putting a fuel pressure gauge inline to see how much its putting out.Tom

Check for proper installation of float needle pull clip.

Reversion, or a float-seat problem?

Reversion needs the fix to occur at the exhaust system config, cam overlap and intake manifold.

Tried a 3rd carb tonight ....It did the same thing, blowing gas out of the bowl...so it must be the mechanical pump...ordered a new one and will take this one off and get it checked out

Inline regulator?

should not need a regulator with a stock fuel pump.I run the Carter street pump without one with no issues.Tom

Really, reversion you say?!
Would that not be making for a backfire condition?

Backfire more likely from a rotor-post mis-alignment, or wiped Exhaust lobe.

Strong reversion under off-idle rhomp is more like a Sneeze, which is usually revealed by a lean-out condition. I think.

Check fuel pressure with an inline gauge. Many of the Edelbrock pumps are known to put out 8 -10 psi and overpower the needle and seat. Some of this has been posted here in this board. If the fuel pressure is that high, install a pressure regulator (Holley has an inexpensive unit) and set to 5-6 PSI delivery.