Engine Performance problem
2003 Chevy Suburban 6 cyl Four Wheel Drive Automatic 75000 miles
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I recently followed your instructions on how to clean the throttle bore. I have a 2003 Chev. Suburban with 5.3L engine. The car can now climb a hill at 10MPH without touching the throttle. How do I fix this problem? I do not see anyway to adjust the TBore. It appears to be electronic? The Tbore alos appears to be slightly opened compared to when I first took the air intake off.

Can you close it by hand? It seems either the cable is binding, or the shat is partially worn, or the tps needs to be replaced.

Yes I can close it by hand.

Try removing the cabe see if it closes by itself, if not check for movement in the shaft, and the TPS for a flat spot.

I do not believe that there is a cable, it appears to be controlled electronically.

REMOVAL & INSTALLATION -2003 Chevrolet Suburban C1500
Page 1 of 2
AIR INDUCTION SYSTEMS
THROTTLE BODY

CAUTION:When battery and some PCM input devices are disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

CAUTION:DO NOT subject a throttle body assembly to an immersion cleaner or a strong solvent with electrical components or sensors attached. Solvents can also wash away or break down the grease used on non-serviceable throttle shaft bearings. DO NOT use a cleaner containing Methyl Ethyl Ketone (MEK). MEK is very strong and can damage components. Never use a wire brush or scraper to clean the throttle body. A wire brush or sharp tools may damage throttle body components.

Removal (4.8L, 5.3L & 6.0L)
1.Disconnect negative battery cable. Drain cooling system into suitable container. Loosen retaining bolt on intake manifold sight shield at top of engine. See Fig. 1. Remove intake manifold sight shield from top of engine. 2.Loosen hose clamp at outlet side of MAF sensor. Loosen air inlet tube hose clamp at throttle body. Remove air inlet tube. Disconnect harness connectors at throttle body. 3.Reposition the coolant air bleed hose clamp at the throttle body. Remove the coolant air bleed hose from the throttle body. Remove throttle body mounting nuts. See Fig. 2. Remove throttle body. Remove throttle body flange gasket and discard.
Fig. 1: Removing/Installing Intake Manifold Sight Shield & Retainer (4.8L, 5.3L & 6.0L) Courtesy of GENERAL MOTORS CORP.
Fig. 2: Removing Throttle Body (4.8L, 5.3L & 6.0L)
Courtesy of GENERAL MOTORS CORP.
Installation
1.Clean gasket surface on intake manifold and throttle body. Install NEW throttle body flange gasket. Install throttle body assembly. Install throttle body mounting nuts and tighten to specification. See TORQUE SPECIFICATIONS. 2.To complete installation, reverse removal procedure. Fill and bleed cooling system. 3.Connect a scan tool to Data Link Connector (DLC), under left side of instrument panel. Turn ignition on, with engine off. Using scan tool, ensure vehicle is not in a reduced engine power mode. Operate accelerator pedal while observing throttle angle on scan tool. Accelerator pedal

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REMOVAL & INSTALLATION -2003 Chevrolet Suburban C1500
Page 2 of 2
should operate freely, without binding, between closed throttle and Wide Open Throttle (WOT).
Removal (8.1L)
Disconnect negative battery cable. Remove the intake air resonator. See Fig. 21. Disconnect the throttle actuator motor electrical connector. Remove the throttle body nuts. See Fig. 3. Remove the throttle body. Remove and discard the throttle body gasket.
Fig. 3: Removing Throttle Body (8.1L)
Courtesy of GENERAL MOTORS CORP.

Installation
1.Clean gasket surface on intake manifold and throttle body. Install NEW throttle body flange gasket. Install throttle body assembly. Install throttle body mounting nuts and tighten to specification. See TORQUE SPECIFICATIONS. To complete installation, reverse removal procedure. 2.Connect a scan tool to Data Link Connector (DLC), under left side of instrument panel. Turn ignition on, with engine off. Using scan tool, ensure vehicle is not in a reduced engine power mode. Operate accelerator pedal while observing throttle angle on scan tool. Accelerator pedal should operate freely, without binding, between closed throttle and Wide Open Throttle (WOT).

© 2007 Mitchell Repair Information Co., LLC.

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