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https://autopapyrus.com/guides/mitsubishi/cedia/intake-manifold-removal-and-installation/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Mitsubishi Lancer Cedia 1.8 (4G93) (2001): Intake Manifold Removal and Installation

On the multipoint-injected 4G93 SOHC, the manifold is attached to the cylinder head with bolts and nuts and is supported by a bracket (stay) to the engine block. The throttle body, fuel rail with injectors, vacuum hoses and wiring harnesses are all mounted on or under the manifold, so most of the time goes into carefully disconnecting everything attached to it. Work on a cold engine.

DifficultyMedium Time2-3 hours Steps14

Key figures

  • Manifold bolt and nut torque
    20 N·m (15 lb-ft). Set it on the torque wrench and tighten from the center toward the ends (step 11). Overtightening risks stripping the threads in the aluminum cylinder head.
  • Manifold bracket (stay) torque
    about 31 N·m (23 lb-ft). Use a torque wrench after tightening the manifold itself (step 11).

Check these values against the manufacturer’s specification for your vehicle before you start.

Diagram: where the intake manifold is and how it is mounted

Intake manifold seen from the front and aboveCylinder headEngine blockbolt at manifoldbolt at block7Head bolts and studs6Dipstick with tube1Intake manifold4Manifold bracket2Fuel rail with injectors5Vacuum hose and connector3Throttle bodyTap to enlarge
  1. 1Intake manifold: cast grey, four curved runners joining a common plenum. Comes off together with the throttle body once everything attached is disconnected. Torque on assembly: 20 N·m, from the middle outward, in two passes.
  2. 2Fuel rail with injectors: a pipe along the head with injectors and plugs. Relieve pressure first and disconnect the supply and return lines (rag underneath), then unbolt the rail. Do not damage the injector O-rings.
  3. 3Throttle body: housing with lever, throttle position sensor and air inlet, bolted to the end of the manifold. Remove the air duct, accelerator cable and bracket; disconnect the heater hoses only after draining coolant.
  4. 4Manifold support bracket: metal bracket from the bottom of the manifold down to the block. Two mounting points: bolts at the manifold and at the block. Torque about 31 N·m: manifold side first, then block.
  5. 5Vacuum hoses and connectors: mark and photograph what goes where before disconnecting, or idle will hunt.
  6. 6Dipstick with guide tube: remove if the tube is fixed to the manifold. Replace the O-ring when refitting the tube.
  7. 7Manifold-to-head bolts and studs: remove evenly from the middle outward. Plug the head ports with a clean rag so nothing falls in.

Parts

3
№PartGenuine part no.Alternatives
01 Intake manifold gasket, Mitsubishi 4G93 (1.8, SOHC) MR507780 AlternativesVictor ReinzAjusaElring
02 Throttle body gasketif needed AlternativesVictor ReinzAjusaElring
03 Dipstick tube O-ringif needed AlternativesVictor ReinzAjusaElring

Part numbers are from the manufacturer's original catalogue. Check them against your VIN before ordering.

Tools

7
  • Socket set and ratchet
  • extension
  • torque wrench (20-31 N·m / 15-23 lb-ft range)
  • screwdrivers
  • hose clamp pliers
  • coolant drain pan
  • marker or small bags for labeling hoses

Step by step

14 steps
  1. Park the car on a level surface and let the engine cool down completely. Disconnect the negative battery terminal. Relieve the fuel system pressure: remove the fuel pump fuse or relay, start the engine and let it stall, then crank the engine with the starter for 2-3 seconds. Cover the fuel line connections with a rag before disconnecting them.
  2. Drain some of the coolant (to a level below the throttle body), because the throttle body on this engine has a coolant passage for heating. Remove the throttle body heater hoses only after draining.
  3. Remove the air duct between the air filter and the throttle body, disconnect the crankcase ventilation hose, and disconnect the mass airflow sensor (if it is mounted on the air duct) together with its connector.
  4. Disconnect the accelerator cable (and the cruise control cable, if equipped) from the throttle body and remove its bracket.
  5. Label and disconnect all vacuum hoses from the manifold and throttle body, as well as the connectors: throttle position sensor, idle air control valve, intake air temperature sensor, and the injector connectors. Take photos of the layout before disassembly, because mixed-up hoses cause a fluctuating idle.
  6. Disconnect the fuel supply line and the return line from the fuel rail (hold a rag nearby, as leftover fuel will spill out). Unbolt the fuel rail with the injectors and carefully move it aside, or remove it completely, taking care not to damage the injector O-rings.
  7. Remove the dipstick and its guide tube if it is secured to the manifold. Replace the O-ring when installing the guide tube.
  8. Unbolt the manifold bracket (stay) from the engine block and, if it gets in the way, the upper engine lifting bracket (hanger).
  9. Evenly loosen and remove the bolts and nuts securing the manifold to the cylinder head, working from the center toward the ends. Remove the manifold together with the throttle body (if needed, the throttle body can be removed from the manifold separately). Make sure nothing falls into the cylinder head ports: plug them with a clean rag.
  10. Remove the old gasket and clean the mating surfaces of the cylinder head and the manifold of carbon and gasket residue (without scratching the aluminum), then wipe them dry. Remove the rags from the ports.
  11. Install the new gasket and the manifold. First snug the fasteners by hand, then tighten the manifold bolts and nuts evenly, from the center toward the ends, in two passes to 20 N·m (15 lb-ft). Tighten the manifold bracket (stay) to about 31 N·m (23 lb-ft), first the bolts on the manifold, then those on the block, to avoid misalignment.
  12. Reinstall the fuel rail with the injectors (lubricate the new injector O-rings with clean engine oil), then reconnect the fuel lines, connectors, vacuum hoses (using your labels or photos), accelerator cable, air duct and dipstick.
  13. Refill the coolant to the correct level and reconnect the battery. Turn the ignition on for 2-3 seconds, 2-3 times (without starting the engine), to build up pressure in the fuel system, and check the connections for fuel leaks.
  14. Start the engine and warm it up until the cooling fan switches on, bleed the air from the cooling system, and top off the coolant. Check for vacuum leaks (hissing, fluctuating idle). If needed, spray carburetor cleaner around the joints: a change in engine speed indicates a leak.

Common mistakes and warnings

  • Work on the fuel system away from open flames and keep a fire extinguisher nearby
  • The manifold torque (20 N·m / 15 lb-ft) and bracket torque (about 31 N·m / 23 lb-ft) are based on data for 4G93 engines; check the torque values for the throttle body, fuel rail and other small fasteners against the manufacturer's specifications
  • If you have no experience working on fuel systems, leave this job to a repair shop