Evaluation of sealed idle mixture adjustment on 1977 Buicks. Report EPA-AA-TEB-81-8

Technical Report · Sat Nov 01 04:00:00 EST 1980

OSTI ID:5474837

Marschall, K E

This report describes the results of an EPA program conducted on 48 in-use passenger cars. Each of these vehicles was a 1977 Buick equipped with a 350 CID engine and a four barrel carburetor. Some of these engines were equipped with special carburetors which had lead plugs covering their idle mixture screws to prevent maladjustments. The purpose of this program was to gather information on current vehicles which will allow EPA to project the effectiveness of similar systems after they have been employed on future vehicles. The program included direct mail solicitation, a parking lot survey, and complete FTP testing. This work was conducted in the Detroit area and at EPA's Laboratory in Ann Arbor during the summer of 1980. The results indicate that this technique for sealing the idle mixture screws is an effective method for preventing the adjustment of the idle mixture. Average idle emission test results for the sealed carburetor vehicles were similar to the results for untampered vehicles with conventional carburetors. Average idle emissions from vehicles with broken or missing limiter caps were substantially higher.

• Research Organization: Environmental Protection Agency, Ann Arbor, MI (USA)
• OSTI ID: 5474837
• Report Number(s): PB-81-132979
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100* -- Internal Combustion Engines
330700 -- Advanced Propulsion Systems-- Emission Control
AIR POLLUTION
AUTOMOBILES
CARBURETORS
DISPERSIONS
ENGINES
EQUIPMENT
EXHAUST GASES
FLUIDS
FUEL SYSTEMS
GASEOUS WASTES
GASES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
MIXTURES
MODIFICATIONS
PERFORMANCE TESTING
POLLUTION
POLLUTION CONTROL EQUIPMENT
SEALS
TESTING
VEHICLES
WASTES