Low fuel pressure with p-pump.

RonA

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Feb 26, 2008
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As rack travel increases and fuel pressure decreases, what happens to injector spray pattern? I am seeing fuel pressure drop down from 36psi to about 10psi when I go to full throttle. Are there going to be noticeable differences when I go to a larger fuel pump that can maintain 40-45psi?

Ron
 
Are you running some type of lift pump? I had the same problem (still might) and we diagnosed that my fass wasnt able to keep up with the fuel the pump was puting out and that decreased presure. You can have the biggest pump in the world, but if your using a stock lift pump its not going to be able to feed it.

If you do have a fass or something like it, it might be time to upgrade to a bigger pusher to keep the PSI up at the pump.
 
fuel psi

You better up grade you fuel transfer system, we stuck a plunger two different times and it hung wide :shake: open, one time on the street and one time in front of the sled, it was not a pretty sight, starving a hi output p pump is scary if you don't have a air shut off, just my 2 cents
 
I understand how to fix it. I would just like to know what difference I will see besides another parts bill and a higher reading on my fuel pressure gauge.
 
I was getting down to about 10PSI with my A1000 pump feeding my 13mm pump last season. We didn't find any internal issues when the pump was torn down.
I was probably down a bit on power though.

For optimal power output, you don't want your fuel pressure to drop below 20-25PSI.
 
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