Fuel pressure fluctuations Procharger M-1 7.4 MPI
#1
Thread Starter
Registered
Joined: Jul 2003
Posts: 224
Likes: 1
From: truckee ca
I have set my fuel pressure a number of times under way in order to achieve WOT with out faltering. Initial 4600RPM then backs down to 4200. The last attempt @ this adjustment got me to 4400 WOT but the fuel pressure would fluctuate wildly between 55#s and 46#s. Is this common or should it be more stable?
#2
If set up correctly fuel pressure is related to the amount of boost you are runing. I set mine with engine off at 43PSI, pressure goes down when engine in running & in vacuum, & goes up past 43 as boost goes up. At 10lbs of boost I have 53psi of pressure. Ths way the difference between the two is always the same.
#3
Registered
Joined: Feb 2004
Posts: 3,710
Likes: 2
From: MT. JULIET, TN.
Blow your vacuum line out and make sure it's not restrcted. Mine was acting up and it had oil in the line causing it not to activate the regulator.





