How do you disconnect the fuel lines from the fuel rail in a 1990 Chevrolet S10 Pickup with a 4.3L V6 engine?
REMOVE or DISCONNECT:
1. THERMAC hose from engine
2. Air cleaner, adapter and gaskets. Discard gasket.
3. Electrical connectors to TPS sensor, IAC valve, Injector(s).
4. Grommet with wires from throttle body.
5. Throttle linkage, return springs, transmission control cable and cruise control cable when applicable.
6. Vacuum hoses, noting positions of hoses.
7. Inlet and outlet fuel line nuts.
8. Fuel line O-rings and discard.
9. TBI mounting hardware.
10. TBI unit from intake manifold.
11. Reverse procedure to install using new O-rings and gasket.
THIS PROCEDURE HAS BEEN UPDATED BY TSB # 89-34-6E, dated 11/88
On vehicles using the model 700 TBI, when reinstalling the TBI unit, tighten the attaching bolts/studs to:
Anytime the TBI attaching bolts/studs are installed or removed, the fuel metering body attaching screws should also be re-tightened to: (53 in.lbs). Be sure to apply thread locking compound to screws such as Loctite 262 before tightening.
Some of this information is from the Alldata automotive information website.
NOTE: All fuel feed and return line attachments in the system are screw type fittings. Always use a backup wrench when loosening or tightening the fittings. Screw fittings used on the two systems utilize O-rings for the fuel feed and return pipes and the two sizes of O-rings are not interchangeable. Any time that the fuel or return pipes are disconnected, inspect the O-rings for cuts or other type of damage and replace as necessary. The flare used on these fuel pipes is not compatible with the flare used on other fuel pipes.
FUEL LINE O-RINGS :
The fuel line O-rings used are made of Viton. They are brown in color. Viton is less affected than rubber by the additives used in many fuels. Therefore, rubber should not be used.
Thanks a lot TH2.