Magnafuel problem
Thread Starter
Joined: Oct 2007
Posts: 604
Likes: 1
From: Gainesville FL
Magnafuel problem I have a built 6L with a Novi 2200x supercharger . I am using a magnaMagn 750 Mp4303 fuel pump @ 96lb injectors. . -12 from the tank to the pump , and -10 from the pump to the fuel rails . @ .5600 rpm the fuel psi drops like a rock from 68lb to around 45lb . I am using a Magnafuel boost reference fpr . What will cause this ? Bad pump or fuel pressure regulator ? Need help .
TECH Regular
Joined: Jun 2012
Posts: 414
Likes: 5
From: SV, AZ
Bigger isn't always better. Bigger uses more electricity, creates more heat and often makes more noise. You want to size it correctly rather than just "yuge bro". I don't understand why so many people still think they need to run such big fuel lines (especially for gasoline).
Is the drop happening on the dyno or on the street/track or both? How are you feeding the fuel to the pump from the tank? How are you returning the fuel into the tank? What size return line? Could be a bad pump. Could be a pump feed issue depending on how you're running everything. Could be the pump can't maintain the pressure on that large a volume of fuel. Could be a few different things too.
Is the drop happening on the dyno or on the street/track or both? How are you feeding the fuel to the pump from the tank? How are you returning the fuel into the tank? What size return line? Could be a bad pump. Could be a pump feed issue depending on how you're running everything. Could be the pump can't maintain the pressure on that large a volume of fuel. Could be a few different things too.
TECH Fanatic
Joined: Jun 2003
Posts: 1,869
Likes: 99
Bigger isn't always better. Bigger uses more electricity, creates more heat and often makes more noise. You want to size it correctly rather than just "yuge bro". I don't understand why so many people still think they need to run such big fuel lines (especially for gasoline).
Is the drop happening on the dyno or on the street/track or both? How are you feeding the fuel to the pump from the tank? How are you returning the fuel into the tank? What size return line? Could be a bad pump. Could be a pump feed issue depending on how you're running everything. Could be the pump can't maintain the pressure on that large a volume of fuel. Could be a few different things too.
Is the drop happening on the dyno or on the street/track or both? How are you feeding the fuel to the pump from the tank? How are you returning the fuel into the tank? What size return line? Could be a bad pump. Could be a pump feed issue depending on how you're running everything. Could be the pump can't maintain the pressure on that large a volume of fuel. Could be a few different things too.
https://ls1tech.com/forums/fueling-i...uel-lines.html
Another thing to look at is the power source to the pump. Are you still running stock wire or 10 gauge dependent upon length of the wire to the pump? Bigger pumps require more amps - some way over 14 amps. Racetronix has a good writeup on why stock wire is not good enough with higher capacity pumps (340,450 etc). AEM specs for their pumps require 13.5 volts at the pump.
Most alternators quit when their rpm exceeds 18k rpm. Spinning the engine to 7 k will exceed the 18k rpm threshold of the alternator. Lots of posts about that as well.
Launching!
Joined: Jan 2018
Posts: 283
Likes: 0
confirm during the fault the voltage at the relay output to the pump and the voltage at the power terminal of the pump.
no way should you be out of pump on gasoline and that power.
might also be worth checking your filter isn't blocked causing a restriction and make sure your tank foam baffles haven't broken up in the tank and aren't restricting the suction.
the suction bowl of the tank is gravity fed I assume? there's no surge tank and/or lift pump?
no way should you be out of pump on gasoline and that power.
might also be worth checking your filter isn't blocked causing a restriction and make sure your tank foam baffles haven't broken up in the tank and aren't restricting the suction.
the suction bowl of the tank is gravity fed I assume? there's no surge tank and/or lift pump?
