Engine Controls - Exhaust Odor and Emission Test Failure
87chevy19Number: 86-253-6E
Section: 6E
Date: October, 1987
SUBJECT: EXHAUST ODOR - INSPECTION/MAINTENANCE (I/M) TESTING
MODELS: 1986 M VANS EQUIPPED WITH 4.3L (VIN CODE Z) ENGINES
THIS BULLETIN CANCELS AND SUPERSEDES TRUCK SERVICE BULLETIN 86-B-115/ CHEVROLET BULLETIN 86-149 DATED AUGUST, 1986, ALL COPIES OF WHICH SHOULD BE DESTROYED.
THIS REVISION MODIFIES THE SERVICE PROCEDURE BY THE ADDITION OF A CONNECTOR BLEED ASSEMBLY AND EXPANDS THE APPLICABLE USAGES TO INCLUDE VEHICLES EQUIPPED WITH MANUAL TRANSMISSIONS.
Some 1986 M vans equipped with 4.3L TBI engines (VIN Code Z) may experience one or both of the following conditions:
1. Hydrogen sulfide related odor typically described as "rotten egg smell" at idle.
2. Difficulty in meeting state exhaust emission inspection/maintenance (I/M) testing requirements.
SERVICE PROM USAGE:
If these conditions cannot be repaired using normal service procedures, a revised calibration PROM and a connector bleed assembly, P/N 10093100, may be installed. See the service PROM usage chart below for the appropriate service PROM part number.
INSTALLATION PROCEDURE:
1. Disconnect the negative battery cable.
2. Install the appropriate service PROM.
FIGURE NO. 1:
3. Disconnect the cap or vacuum line currently on port J on the front of the TBI unit. (See Figure No. 1).
4. Install connector bleed assembly, P/N 10093100, by sliding the rubber end on to port J.
5. Connect the vacuum line or cap removed from port J to the open end of the connector bleed assembly.
6. Reconnect the negative battery cable.
Labor Operation Number: T7430
LaborTime: .4 Hour