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Engine Controls - Hard Start, Rough Idle, and Stalling

Bulletin No.: 002/94
Issued: 3/16/94
Revised

Category
F

Applicable Model/s
1991-92 Navajo

Subject:
HARD COLD START AT TEMPERATURES BETWEEN 30-70 DEGREES F (-1 -21 C)

APPLICABLE MODELS/VINS
1991-92 Navajo

DESCRIPTION

Long starting times and rough idle with stalling or near stalling on initial start up may be caused by low volatility in some fuels used in warmer climates from May to September. A new EEC IV processor may be installed to correct this problem. Use the diagnostic procedures to determine if installation is necessary.

INSPECTION PROCEDURE

1. With the temperature between 30-70 degrees F (-1 -21C) and the vehicle not started previously, verify that the engine start time is greater than four (4) seconds and can be made to start by cycling the key off and on before the second attempt.

2. If the engine starts in a reasonable amount of time and then idles rough or stalls, follow the diagnostic procedures below to determine it the EEC processor requires replacement.

DIAGNOSTIC PROCEDURE

1. Confirm the electric fuel delivery system meets fuel pressure and leak down time specifications. Follow the instructions in section F of the workshop manual. Service as required.

2. If no service is required and the problem still exists, proceed to step 4. If the problem is no longer present, proceed to step 3.

3. If the start time exceeds two (2) seconds, or it the start time is less than two (2) seconds but requires cycling the key off and on, proceed to step 4.





4. Install a new EEC IV processor. Refer to the table above for correct part usage.

5. Verify the problem does not exist. If the problem is still present, refer to the diagnostic procedures in the workshop manual. Service as necessary.

WARRANTY INFORMATION
(Applies To Vehicles Covered Under Normal Warranty)

Warranty Type: A
Customer Comment Code: 02
Damage Code: 99
Part Number Main Cause: ZZL0 18 881
Quantity: 1
Operation Number/Labor Hours: F0812XRX / 0.6Hr Replace PCM
F0001XDX / 0.3Hr Fuel Pressure And Leak Down Test
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