Navajo 2WD V6-4.0L OHV (1992)
Engine Control Module: Customer Interest
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.
