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Fuel Pressure Dropping at boost

bocou92

New member
My car is with my mechanic getting a dyno and everytime it starts to get boost, fuel pressure drops. Just got the zzp 3.4 pulley, zzp fuel rails, and stg 2 intercooler just added. I've been riding with full zzp exhaust 3", their ECM upgrade, and Cai. I've replaced the pressure regulator which thought it worked. Anyone have any ideas?
 


@Fivefingerdeayhpunch what would cause the voltage to drop though? Maybe an old pump?

@BrandonHall10 it has a few years on it. Probably be a good time to replace
 
Small wiring.

This is going way back here but I remember the power wire to the pump on the 97-03 cars was rather small. You would increase the wire size to provide more voltage to the pump and keep it constant.
 
Yep.. W bodies suffered from small wiring and when rpm are high you are using more power on ignition etc etc. There was a better gauge harness you could add on with a relay so it was directly off the main power.
 


I guess that would make sense cause I had to wire in an electric water pump for the intercooler. I'll have my guy test the voltage. Thanks guys I'll post again if anything else happens
 
It's fun to do. As long as the car is pre 2004 it'll have the hatch in the trunk, at which point he can probe the wires and go for a ride with extension wires and his multimeter up front or a person in the back watching.
 
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