Carburetor - Hesitation or Rough Idle With Warm Engine

Category 4
Applicable Model/s 1983-84 GLC
Subject IMPROVEMENT OF DRIVEABILITY SUPPLEMENT
Bulletin No. 007/84
Issued 10/15/84
Revised

Float Level Checked With Mirror:

DESCRIPTION

If hesitation or rough idle with engine fully warmed occurs on 1983-84 GLC vehicles, please use the following procedure to correct the problem.

1. Verify that all the procedures on the Service Bulletin, Category 4, 003/84, "Improvement of Driveability", have been completed, with emphasis on the following:

^ Check that all countermeasure parts have been installed. (Page 2-3)

^ Check that the duty fluctuates between 20-70 degrees dwell. (Page 9).
^ Check that the float level is correct. Use a mirror to check the float level as shown. If the float level is not checked with a mirror as shown, an erroneous reading will be obtained. (Page 8)
2. Ask the customer what fuel is used in the vehicle. If gasahol or fuels blended with methanol are used, the following driveability problems may occur:

^ Hard start after the engine has been stopped for 10-60 minutes.

^ Stall and rough idle after starting the engine.

If gasahol or fuels blended with methanol are used, advise the customer to discontinue the use of these fuels.

Removing Plunger From Solenoid:

3. Check that the slow fuel cut solenoid valve is not sticking intermittently. Remove the plunger from the solenoid and reinstall the solenoid. Road test the vehicle.

NOTE: Be careful not to drop the spring located inside the solenoid.

The spring can be installed only one way in order to fit flush in the solenoid.
If the driveability problem of rough idle or hesitation idle after a stop no longer occurs, the slow fuel cut solenoid valve is faulty. Replace the solenoid valve with the newly established part (E563 13 XKO).

CAUTION: All procedures in the Service Bulletin, Category 4, 003/84, "Improvement of Driveability", apply only to 1983-84 GLC vehicles.

The A/F Solenoid and Accelerator Pump Kit introduced in 1984 to correct driveability problems on the GLC ATX models has been carried over to the 1985 models. Please note the following cautions:

1. There is no interchangeability of the accelerator pump lever and linkage of the A/F Solenoid and Accelerator Pump Kit and the 1985 model carburetor. Do not install this kit on 1985 models.

2. The A/F Solenoid and Accelerator Pump Kit is for 1983-84 GLC ATX only. Do not install this kit on 1983-84 GLC MTX models.