Engine - Slow Rough or No Idle
90chrysler11 Models1978 to 1982 1.7L & 2.2L Engines With Holley Carburetor Models 5220 & 6520
Subject
Engine Will Not Idle or Will Idle Slow or Rough
Index
FUEL
Date
August 23, 1982
No.
14-32-82
P-2283-C
SYMPTOM/CONDITION
Vehicle operates satisfactorily, then suddenly develops a poor idle or no-idle condition while maintaining satisfactory off-idle operation due to idle circuit plugging.
DIAGNOSIS
Connect a tachometer to engine. Start engine and allow to fully warm up.
Remove air cleaner crossover and look down primary venturi throat of carburetor.
If fuel is seen to be dripping or flowing from the venturi nozzle, place your finger over the idle air bleed and slowly turn the solenoid idle speed adjusting screw counterclockwise.
If engine will idle to specification with no nozzle drip then remove your finger from the idle air bleed. If the engine dies the idle fuel circuit is plugged or restricted. Follow repair procedure outlined below:
NOTE: The solenoid idle stop may have been adjusted far beyond the normal curb idle setting, starting the venturi nozzle dripping, in an attempt to remedy the no-idle condition.
REPAIR PROCEDURE
1. Thoroughly warm up engine.
2 . With the transaxle in neutral and the parking brake
applied, place the fast idle speed screw on the top (highest) step on the fast idle cam.
3. Next, manually close the choke blade as much as possible without stalling the engine, while at the same time, covering the idle air bleed port with your finger. Do this for about 20 seconds, two or three times in a row. The high vacuum level generated in the idle system during this procedure should "pull out" the foreign material.
4. Return throttle to the curb idle position and:
a. If the problem has been remedied, set idle speed to specification and shut off engine.
b. If some improvement is noticeable, but the idle does not yet seem "right," repeat Steps 2 and 3 to see if further improvements can be made.
c. If no improvement is observed, go to Step 5.
5. Shut off engine and apply shop air (no greater than 60 P.S.I.) to the idle air bleed port. Use caution when doing this because the pressure will probably blow fuel straight up from the carburetor's internal vent area.
6. Restart engine and attempt to adjust curb idle speed. If this procedure fails to give a satisfactory idle, follow the procedure in Step 7 below.
7. Remove the carburetor air horn.
Apply shop air to all air bleed and fuel circuits in both the main body and air horn repeatedly blowing out the circuits in an alternating pattern.
Replace carburetor air horn. Start engine and attempt to adjust curb idle speed.
8. If the above procedures do not resolve the problem, or if the problem recurs, a thorough bench teardown and cleaning of the carburetor will be required.
POLICY: Information only