Beretta V6-173 2.8L (1989)
Fuel Injector: Technical Service Bulletins
Multec Port Fuel Injectors - Cleaner Precautions
Number:
91-312-6E
Section:
6E
Date:
MAY 1991
Corp. Bulletin No.: 116502R
Subject:
MULTEC PORT FUEL INJECTORS/CLEANING
Month and Year:
1986-90 CELEBRITY
1986-91 CAMARO, CAVALIER, CORVETTE
1987-91 CORSICA, BERETTA
1990-91 LUMINA, STORM
Figure 1
THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-28O-6E, DATED APRIL 1991. THE STORM HAS
BEEN ADDED. ALL COPIES OF 91-280-6E SHOULD BE DISCARDED.
This bulletin has been written to inform technicians of possible damage to Multec port fuel injectors as a result of cleaning.
The ball and seat design of the Multec port fuel injectors eliminates the need of ever having to use an injector cleaner. By design, the fuel metering
portions of the injector are not directly exposed to the intake manifold gases that are responsible for the build-up of deposits that can cause injectors to
clog. (see Figure 1).
Some of these cleaners may contain high percentages of methanol and other solvents that cause damage to the injectors' coil wire insulation. Damaged
insulation results in low resistance or shorted injectors. Also, high percentages of methanol or other solvents can increase friction at the injectors'critical
bearing surfaces, resulting in premature wear.
General Motors has conducted extensive injector cleaning studies to determine effectiveness. There is no confirmed evidence that cleaning Multec port
fuel injectors has resolved a vehicle driveability problem. In addition, suppliers of various injector cleaners may claim that their product can also clean
intake valve deposits. General Motors laboratory tests have shown that injector cleaners have little or no effect on intake valve deposits.
