14500 & 02: Installation Instructions for LT1 Throttle Bodies
Installation Instructions for 14500 & 14502
Throttle Body 1992-1997 LT1
Throttle Body Assembly w/ Linkage
Additional Cable Sheave
(4) Mounting Bolts
(7) Machine Screws
(7) Lock Washers
Gasket – T.B. to Intake Plenum
Gasket – T.B to Water Crossover Manifold
Let engine cool. Open hood and disconnect negative battery terminal.
Remove the throttle body inlet hose and disconnect the two water lines from the underside of your stock throttle body.
Disconnect all vacuum hoses, electrical connectors, throttle cable, and cruise control cables from your stock factory throttle body.
Remove the four mounting bolts holding the throttle body to the intake plenum. Remove slowly making sure there are no additional connections you have overlooked.
Remove the (7) Torx screws that hold the water crossover manifold to the bottom of the stock throttle body and move it to the new throttle body using the supplied new gasket and the supplied new (7) black machine screws and split lock washers. Do not reuse the original Torx screws. Note: Screws may become tight at bottom of travel. Be sure that the water manifold is seated tightly against throttle body to avoid any leaks.
Remove the throttle position sensor (TPS) from the stock throttle body and move to the new Professional Products throttle body using the original screws.
Note that the 52mm throttle body does not have to be port matched to the intake, but the 58mm should be.
Install new throttle body to the intake plenum using the (4) supplied socket head cap screws. Torque to factory specifications.
Check the TPS voltage reading with a digital voltmeter and adjust to factory specifications. On highly modified vehicles you may have to slot the holes in the TPS in order to allow it to rotate to the correct position to achieve the proper voltage reading.
Reattach the negative battery cable. Refill the coolant tank to allow for any lost coolant. Reattach all of the connections that were originally detached. See note below regarding inlet hose.
Start engine. Idle adjustment is made with the set screw that has yellow paint on it. Loosen jam nut, turn screw (requires a Torx style screwdriver) to achieve desired idle, and tighten the jam nut. An hour of city driving may be required for computer to properly adjust idle speed.
SPECIAL NOTE: If you need to switch the linkage on your throttle body, pay particular attention to the positioning of the spring before you remove the existing linkage. Try to hold the spring in its original position while you remove the original linkage and replace it with the one needed for your application. Check to make sure the spring is properly positioned after assembly.
Inlet Hose Note: If you have trouble getting your stock rubber inlet hose over this larger throttle body inlet, soak it in boiling hot water for a few minutes which will expand it enough to allow you to slide it onto the throttle body. Coating the throttle body with WD-40 or silicone spray will also help. Be careful not to burn yourself on the hot water.