Cutlass Ciera FWD L4-151 2.5L (1982)
Choke Pull-off: Customer Interest
CEngine - Hard Start/Poor Warm Up Performance
SUBJECT
CARBURETOR VACUUM BREAK
NUMBER: 84-T-24
TESTING PROCEDURE
DATE:
March 1, 1985
MODELSNEARS
ALL MODELS WITH CARBURETORS
EQUIPPED WITH VACUUM BREAKS
SECTION: 6C
Hard starting or poor warm-up performance on a carbureted engine may be due to a leaking vacuum break unit. The vacuum break, sometimes called the
"choke pull-off," opens the carburetor choke valve against the tension of the thermostatic choke coil during cold engine start-up. A vacuum break unit
with a leaking diaphragm will not open the choke valve to the proper position, and may cause a cold engine to load up with fuel, resulting in black
exhaust smoke..
FIGURE 1
VACUUM BREAK TESTING PROCEDURE:
1.
Determine whether the vacuum break has a bleed orifice. If it does, it should be plugged as shown. See Figure 1 for possible locations.
^
Most rear or secondary side units have a bleed.
^
Most front or primary side units do not.
