Vortech 1999-2006 4.8L/5.3L/6.0L Light Truck/SUV User Manual

Page 19

P/N: 4GL020-010

08OCT08 v5.0(99-07 GM Trk (4GLv5.0))

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