Q: How to Remove and Replace the Throttle Body Assembly on Jeep Wrangler?
A: Detach the cable from the negative battery terminal. Detach the vacuum hoses from the throttle body upper bonnet. Release the mounting clips and remove the upper bonnet. Remove the three mounting nuts and lift off the lower bonnet. Remove the gasket from the rim of the throttle body. Disconnect the ISA motor harness connector. Detach the fuel supply and return lines from the throttle body. Remove the Accelerator Cable and return spring. Detach the wire harness connector from the injector by compressing the lock tabs and lifting up. Identify and label the vacuum tubes at the back of the throttle body. Detach the vacuum tubes from the throttle body. Detach the TPS connector. Remove the throttle body mounting nuts and remove the throttle body. Remove any old gasket material or dirt from the mating surfaces of the intake manifold and the throttle body. If you are replacing the throttle body assembly, remove the ISA motor and Throttle Position Sensor. Install them on the replacement throttle body and adjust them. Installation is the reverse of removal. Be sure to use a new gasket and tighten the mounting nuts.
Q: How to check and fix a vacuum leak in the carburetor or throttle body on Jeep Wrangler?
A: The carburetor, Throttle Body Injection (TBI) unit or throttle body on multi-port fuel injected models is attached to the intake manifold by four bolts or nuts. These fasteners can sometimes work loose from vibration and temperature changes during normal engine operation and cause a vacuum leak. If you suspect that a vacuum leak exists at the bottom of the carburetor or throttle body, obtain a length of hose. Start the engine and place one end of the hose next to your ear as you probe around the base with the other end. You will hear a hissing sound if a leak exists, but be careful of hot or moving engine components when performing this check. Remove the air cleaner assembly, tagging each hose to be disconnected with a piece of numbered tape to make reassembly easier. Locate the mounting nuts or bolts at the base of the carburetor or throttle body. Decide what special tools or adapters will be necessary, if any, to tighten the fasteners. Tighten the nuts to the specified torque. Don't over tighten them, as the threads could strip. If, after the nuts or bolts are properly tightened, a vacuum leak still exists, the carburetor or throttle body must be removed and a new gasket installed. After tightening the fasteners, reinstall the air cleaner and return all hoses to their original positions.
Q: How to replace Fuel Injector,Fuel Pressure Regulator,Throttle Body and Throttle Position Sensor on Jeep Wrangler?
A: For the fuel injector, remove the throttle body upper and lower bonnets. Detach the injector connector and remove the retainer. Discard the centering ring and upper and lower O-rings. Install the replacement O-rings and centering ring. For the fuel pressure regulator, remove the throttle body and the pressure regulator mounting screws. Remove the housing, spring, spring seats, diaphragm, and pivot. Clean the housing and reinstall the components. To replace the ISA motor, disconnect the ISA motor harness connector and detach the throttle return spring. Remove the mounting nuts and the ISA motor from the bracket. Reinstall the motor.