The specification calls for 900 rpms for the idle speed when warm for the 1987 Dodge Shadow.
One can adjust this with a screw on the carburetor, if it has one.
If it's fuel injected the idle speed is automatically controlled.
Fast Idle Speed
HOLLEY 5220/6520
Fig. 5: Turn the adjusting screw with a screwdriver to raise or lower the fast idle speed — make sure that the adjusting screw is resting against the lowest speed step
NOTE: This procedure is performed while the carburetor is installed on the engine.
- On 1981–82 cars, disengage the two-way electrical connector at the carburetor (red and tan wires).
- On all years, disconnect the jumper wire at the radiator fan and install a jumper wire so that the fan runs continuously.
- On 1983–86 models, pull the PCV valve out of the valve cover and allow it to draw underhood air.
- Disengage the oxygen sensor system connector located on the left fender shield near the shock tower.
- Ground the carburetor switch with a jumper wire.
- Open the throttle slightly and place the adjustment screw on the slowest speed step of the fast idle cam.
- With the choke fully open, adjust the fast idle speed to comply with the value indicated on the underhood sticker.
- Return the vehicle to curb idle, then reposition the adjusting screw on the slowest speed step of the fast idle cam to verify fast idle speed. Re-adjust as necessary.
- Turn the engine OFF, remove the jumper wire and reconnect the fan.
- Reinstall the PCV valve and remove the tachometer. On 1983–86 models, reattach the oxygen sensor system connector, and remove the jumper wire from the carburetor.
Fast Idle Opening
MIKUNI
- Before adjustment, leave the carburetor alone for approximately one hour at 73°F (23°C).
- Adjust the fast idle opening by turning the fast idle adjusting screw to the following specified values (drill diameter):
- 2.6L engines equipped with manual transaxles — 0.028 in.
- 2.6L engines equipped with automatic transaxles — 0.031 in.
Choke Valve Setting
MIKUNI
Fig. 6: After tightening the choke cover lockscrews, cut the heads off of lockscrews A (total of 3 screws) and stake the heads of lockscrews B (total of 2 screws) with a blunt punch
NOTE: This procedure need only be performed if the carburetor is disassembled.
- Fit the strangler spring to the choke lever.
- Assemble the choke valve, aligning the inscribed line or black painted line on the tooth of the choke pinion with the inscribed line on the cam lever.
- Temporarily tighten the new lockscrews.
- Set the choke valve by moving the pinion arm up or down, align a punched mark on the float chamber cover at the center of the three inscribed lines, and secure the pinion arm with the lockscrews.
- Install the choke cover and tighten the lockscrews.
- Cut off the heads off of lockscrews A.
- Stake the heads of lockscrews B using a blunt punch.
Vacuum Kick
HOLLEY 5220/6520
NOTE: This procedure is performed while the carburetor is installed on the engine.
If the vacuum kick is adjusted to open the choke too far, the engine may stall or idle very roughly just after cold start. If it is adjusted so that the choke does not open enough, there may be black smoke in the exhaust.
NOTE: To perform this procedure, you will need a hand held vacuum pump capable of producing at least 15 in. Hg (50.6 kPa) of vacuum. The vacuum kick diaphragm may be damaged if you attempt to retract it manually. You will also need a drill or dowel which has a diameter equivalent to the specification for Vacuum Kick in the Carburetor Specifications Chart.
- Remove the air cleaner. Open the throttle, close the choke and hold it in the closed position, and then release the throttle to trap the fast idle cam in the choke-closed position.
- Disconnect the vacuum hose at the choke vacuum kick diaphragm. Connect a vacuum pump and apply 15 in. Hg (50.6 kPa) or more of vacuum.
- Gently move the choke blade toward the closed position just until play is eliminated from the vacuum kick linkage (so that the vacuum kick is determining choke blade position).
- Insert the drill or dowel into the gap between the upper edge of the choke blade and the air horn wall, toward the center of the gap. The dowel or drill should just fit into the gap. If necessary, rotate the Allen head screw in the center of the diaphragm housing to create the proper gap and then recheck with the measuring device.
- Restore all vacuum connections and reinstall the air cleaner.
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