The 2.8 4JB1 boosts to 16-17psi as stock. 10psi seems low...

A 1.8 may use more fuel as it is working harder.


1989 3.1 Isuzu Bighorn Hybrid

2" Lift with longer shocks
31.10.50R15 Recip Trials
Full 2.5" free flow stainless system
Front mount intercooler
Pump tuned
4.56 Diffs