Genuine Chevrolet Astro Throttle Body

Chevrolet Astro Throttle Body Parts Questions & Experts Answers

• Fuel Meter Body Kit
  17078262
  Q: How to check and replace Fuel Injector,Fuel Pressure Regulator,Throttle Body,Throttle Position Sensor,Intake Manifold and Idle Control Valve on Chevrolet Astro?

  A: The CMFI or CSFI component tightly controls fuel supply in the engine located at the lower intake manifold center. Among other features, a CMFI system has an adjustable aluminum air intake plenum and one non-serviceable fuel injector unit; while a CSFI system comes with non-adjustable air intake plenum, six individually controlled fuel injectors and it incorporates a Mass Air Flow sensor. The PCM tracks various engine parameters by means of sensors and energizes the Fuel Pump briefly upon ignition. Fuel is delivered into cylinders via poppet nozzles in tubes by a high-pressure electric pump found inside the tank of the fuel regulated by a pressure regulator of fuel. This is accomplished by an Idle Air Control valve that regulates additional air flow. Multiple steps must be taken for upper intake manifold removal such as disconnecting battery, relieving fuel pressure, removing components as well as disconnecting different connectors together with hoses. Installations are done inversely to their removals. A similar procedure which involves disconnection of battery, relief from pressure on fuels and also taking away related components is used to remove CMFI as well as CFIS fuel injection units (CMFI). Fuel Injectors are inspected for faults and replaced if necessary. Idle Air Control (IAC) Valve checks resistance and operation during idle speed control checkups. Several steps for removal and installation including resetting IAC Valve are provided in this respect. Intake Manifold Tuning Valve (CMFI) must be checked for replacement when necessary. Fuel Injector Replacement (CSFI) calls for detachment of the fuel meter body from its installation place back again into it after fixing it up (CSIF). The Fuel Pressure Regulator (CSFI) would be replaced following o-ring replacement among other specific steps. Throttle Body Removal/Installation (CSFI): Disconnect various components , ensure proper cable operation etc. In details, Throttle Position Sensor (TPS) checks involved backprobing, removal of mounting screws and alignment during installation.
• Fuel Meter Body Kit
  17111989
  Q: How to remove and install Fuel Injector,Fuel Pressure Regulator,Throttle Body,Throttle Position Sensor and Idle Control Valve in Model 700 Throttle Body Injection on Chevrolet Astro?

  A: The first step is to relieve fuel pressure and disconnect the battery's negative terminal before performing various maintenance actions on the throttle body assembly. If you are working on a fuel injector, ensure that its electrical connector is removed, the injector retainer screw is taken off, and it is pried out gently to access upper and lower O-rings that are replaced upon removal. Also check the fuel injector filter and clean out dirt in fuel lines and tank. When installing a new O-ring, lightly lubricate it with transmission fluid and make sure it is positioned correctly. In terms of direction, push the injector assembly straight into the fuel injector cavity, aligning the electrical connector end. Fasten it down using a threaded locking compound applied to the retainer screw. Thereafter, reinstall the air cleaner housing assembly, adapter, and gaskets while checking for fuel leaks with engine off and ignition on. Regarding the steps involved in removing a fuel pressure regulator, remove four attaching screws holding down a pressure regulator cover assembly while keeping regulator compressed; replace a pressure regulator diaphragm assembly when necessary. Install the new diaphragm first followed by the spring seat then spring ensuring proper seating of diaphragm so that it doesn't get twisted or wrinkled while being installed or used henceforth. Replace diaphragm over mounting holes before fixing with four screw assemblies coated with thread locking compound. The negative battery cable should be reconnected and check for any other fuel leaks before you shut off engine/ignite on again. In order to keep Throttle Position Sensor (TPS) functional unplug its electrical connector; remove two attaching screws; close throttle valve; position TPS on throttle shaft before refitting; rotate counter-clockwise until mount holes are aligned then secure with two attaching screws. As soon as this process ends put back air cleaner housing assembly, adapter plus gaskets connecting cable at negative battery terminal again.In case of an Idle Air Control (IAC) valve, unplug wiring connection going straight to the IAC valve and then remove the IAC valve mounting screws before taking out IAC. Replace O-ring, clean seating surfaces of the IAC valve. If it is fully extended, measurement should be taken between the valve pintle tip and flange mounting surface; if this exceeds the set specifications bring it down to avoid damaging the part. As you retract IAC valve into its bore in throttle body apply a little transmission fluid on new O-ring for lubrication purpose and to prevent it from getting cut during this process. Fasten IAC valve securely with thread locking compound on attaching screws plus connect electrical connector. Finally re-install air cleaner housing assembly, adapter and gaskets while reconnecting battery cable. Start engine and let it warm up sufficiently until PCM will establish correct idle speed.For Tube Module Assembly, remove tube module assembly attaching screws; discard old gasket as well as any remaining material of gasket at throttle body. Install a new tube module gasket and the tube module itself after cleaning both areas thoroughly.Reinstall air cleaner housing assembly, adapter and gaskets.The Fuel Meter Assembly can be maintained by removing fuel meter assembly from throttle body injection unit, two fuel meter body attaching screws and washers.If a new fuel meter is being installed transfer fuel pressure regulator and fuel outlet nut to it from old meter.Discard old fuel meter body-to-throttle body gasket as new one is put in its place.Make sure that you get the correct cutouts matching each other in order to install fuel meter onto throttle body tightening screw adequately.Upon removal of Throttle Body Assembly, unplug electrical connectors from fuel injector, IAC, TPS.Remove old throttle body-to-Intake Manifold gasket with throttle body mounting studs.Install new one on tube module assembly.IAC valve as well as TPS should also be mounted on throttle body assembly.Install a new fuel meter body-to-throttle body gasket aligning cutouts with openings.Insert fuel injector and the fuel meter assembly at this stage.Finally, install throttle body assembly on intake manifold using new throttle body-to-intake manifold gasket and tighten mounting studs to specified torque values.Minimum idle speed adjustment requires you to ground the diagnostic terminal of the ALDL connector, turn on the ignition, wait 30 seconds, unplug the IAC valve electrical connector, start the engine and adjust a particular idle stop screw with transmission in Neutral (manual) or Park (automatic) to achieve certain RPM. After that reattach IAC valve electrical connector again; remove any vacuum line ports that might still be present and reinstall air cleaner housing assembly, adapter plus gaskets. For non-adjustable TPS output check, using a digital voltmeter connect it from center terminal "8" to outside terminal "A" of TPS connector.With engine off but ignition on TPS voltage should not exceed 1.25 volts in such case. If this exceeds specifications replace TPS.
• Tbi Throttle Body Assembly
  17111717
  Q: How to remove and install Fuel Injector,Fuel Pressure Regulator,Throttle Body,Throttle Position Sensor and Idle Control Valve in Model 220 Throttle Body Injection on Chevrolet Astro?

  A: Start by relieving system fuel pressure and disconnecting the battery's negative terminal to perform maintenance procedures on the throttle body assembly. After that, take off the air cleaner housing assembly, adapter, and gaskets. Regarding the Fuel Meter Cover/Fuel Pressure Regulator Assembly, unplug the electrical connectors to the fuel injectors and remove both long and short fuel meter cover screws, to allow for removal of fuel meter cover. Then take out the cover if there is any dirt on it; additionally one should replace such seals as a fuel meter outlet passage gasket, pressure regulator seal or a cover gasket and then clean up its surface if necessary. Eventually install new gaskets and seal as well as put back the fuel meter cover assembly having used Loctite 262 on all screws. Reinstall the electrical connectors to injectors together with battery cable while checking for leaks with engine off and ignition on prior to reinstalling the air cleaner housing assembly along with its adapter and gaskets. In case of Fuel Injector Assembly unconnect electrical connectors from fuel injectors, remove Fuel Meter Cover/Pressure Regulator Assembly and using a screwdriver gently take out them from their seats. The injector consists of upper O-rings, lower O-rings as well as filter which need inspection for dirt or contamination after being removed from an injector; therefore, use another part including an identical replacement injector while sliding in a new filter then lubricating or installing new O-rings before pushing it into a fuel meter body. When replacing an IAC valve, make sure that you unplug its electrical connector before undoing it with an adjustable wrench. Take away old IAC valve gasket that should be discarded afterwards leaving throttle body clean while making measurements at different pintle positions. Finally adjust pintle if required after putting back new gasket before returning IAC valve completely for correct torque specifications when installing it. Reconnect the electrical connector and install air cleaner housing assembly, adapter and gaskets. As for the Fuel Meter Body Assembly, disconnect electrical connectors from fuel injectors and remove Fuel Meter Cover/Pressure Regulator Assembly, Gaskets and Seals. Remove the fuel injectors, unscrew the fuel inlet and return line threaded fittings, detach lines with O-rings removed. After removing the fuel outlet nut or gasket as well as the inlet one, put on a new throttle body-to-fuel meter body gasket then place the fuel meter body assembly via throttle body. Before tightening these screws to not forget to apply thread locking compound on them; thus use thread locking compound on the attaching screws of the fuel meter body-to-throttle body assembly. Install new gaskets as well as inlet-outlet nuts followed by installing it with a new TBI-to-manifold gasket and new O-rings on fuel line nuts. The air cleaner housing must be reinstalled together with adapters, gaskets. Finally, unplug all electrical connectors; remove the throttle linkage, return spring(s), transmission control cable (automatics), cruise control if equipped, detach vacuum hoses labeling them accordingly that they can be reattached later during reassembly. To remove the inlet and outlet fuel line nuts using a backup wrench removing those fuel line O-rings next are five TBI mounting bolts which lift that TBI unit up out of intake manifold where its old TBI manifold gasket will also be discarded. Put it onto a holding fixture if available or take care while working directly on benchtops without any additional protection against damages or spills when possible such as placing it directly upon top of another workbench. When cleaning up an individual part from dirtiness by inspection of mating surfaces as well as reinstallation of IAC valve or TPS do not forget to invert throttle body in order to remove IAC valve after taking off throttle body assembly including its old throttle body-to-fuel meter body gasket, the TPS or those screws attaching the fuel meter body to throttle body. Place fuel meter body assembly onto throttle body, secure it with thread locking compound on attaching screws and then install a new throttle body-to-fuel meter body gasket. Next the TBI unit with a new TBI-to-manifold gasket and new O-rings on fuel line nuts should be installed. As for vacuum hoses, throttle linkage, return spring(s), transmission control cable (automatics), cruise control cable and grommet with wire harness that returns through throttle body; after which all these parts can be reassembled back into place. Plug all electrical connectors in followed by connecting negative battery cable before checking to see if there is any fuel leaking with an engine off and ignition on. Set minimum idle speed in addition to TPS output values then reinstall air cleaner housing assembly adapter gaskets so as to finalize maintenance activities.