Vortech 1999-2006 4.8L/5.3L/6.0L Light Truck/SUV User Manual
Page 19
P/N: 4GL020-010
©2008 Vortech Engineering, LLC
All Rights Reserved, Intl. Copr. Secured
08OCT08 v5.0(99-07 GM Trk (4GLv5.0))
9
8.1 FUEL MAnAGEMEnT UnIT RECALIBRATIOn
(2000 Models, 2002 4.8L Only)
A. Remove the six allen head screws on
top of the fuel management unit (FMU).
(See Fig. 8.1-a.)
B. Remove the diaphram and 10:1 disk (2.47” O.D.)
and ring from inside of the FMU.
C1. For 2000 5.3L and 2002 4.8L trucks: Install the
replacement 8:1 ring (with notched part facing
down) around the four screws inside the FMU.
(The 8:1 components are smaller in diameter
than their 7:1 counterparts.) Place the 8:1 disk
(2.22” O.D.) inside the ring on top of the pis-
ton.
C2. For 2000 6.0L trucks: Install the replacement
12:1 disk (2.72” O.D.) into the FMU.
D. Install the new diaphram and carefully line up
the holes to the body.
E. Reinstall the FMU cover with the six allen head
screws. Do not over-tighten the screws. The
correct torque is 24 in/lb (2 ft/lb).
Fig. 8.1-a
WARNING: Do not remove the four screws
holding the valve body. Once
taken apart the valve would have
to be replaced.
WARNING: For 2000 model year 5.3 & 6.0L
and 2002 4.8L vehicles, complete
Section 7 (previous step). Perform
this step then proceed with Section
8 in the instruction manual