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summit fuel pump - 8-9 psi fuel pressure too high?

10K views 6 replies 7 participants last post by  Xack  
#1 ·
the other day i noticed my fuel pressure on my fuel line has been dropping below 5psi and mostly is at 4psi. and i recall the street avenger carb requiring minimum of 6psi. so obviously the 4psi fuel pressure explains why i had certain stalls at times and haves to really rev the motor up to keep it from dying.

i didn't want to go back to a STOCK fuel pump that can barely put out the 6psi minimum so i ordered up a summit pump. i got her in today and she's cranking out 8-9psi to the carb. is that too high of a pressure? recalling back to auto mechanic school days, we were thought fuel pressure for a carb'ed car should be 5-7.

also would of been nice for the pump to indicate which side is IN and OUT.:mad::mad:
 
#2 ·
I think it depends on the needles and seats you are utilising some will take more pressure than others . If I remember right the viton tipped units are good to around 9 psi . Not sure somenone else will chime in I am sure .
 
#5 ·
just so people know,and its kind of funny this came up today, but stock scj,and cj 429s were 8.5 pounds from factory, the vtron seats will hold up to about 15, we run 9 to 12 most of the time



-rich

min req was 8.5 @at carb,
 
#6 ·
also would of been nice for the pump to indicate which side is IN and OUT.:mad::mad:
Haha I used the same pump and wouldn't ya know it....I ran the lines backwards. My pump also wasn't marked in or out, but when I energized the pump to fire the engine for the first time I heard bubbles in the fuel cell. I actually just reversed the polarity for the initial start. I then loosened the clamp that secures the pump and spun it, hooked the lines back up and corrected the polarity.
 
#7 ·
Summit Mechanical Pump is only at 4.5 psi

My Summit Mechaincal pump only puts out 4.5 psi. I'm usding an Edelbrock 750 Carb. I called Edelbrock and they say that it should be fine. Of course she's stumbling around 2000 rpm. It seems to idle OK and at more than 2500 it smooths out. I hope I can compensate the curve on the timing.