Zephyr L6-200 3.3L (1982)
c.
If RPM still does not drop, remove valve from the propane bottle. Reverse flush the valve with compressed air to remove contaminants that
may prevent full propane flow, and repeat step 13.
d.
If RPM still does not drop, check propane tool side valve. The valve should be fully open after one turn counterclockwise. Service or replace
valve as required and repeat step 13.
15.
If propane gain is within specifications, note the following:
a.
Vehicles with zero gain and zero is the minimum gain specified, proceed to speed drop test, step 17.
b.
All other vehicles with propane gain to specification, note the following: All carburetors proceed to step 18.
16.
If propane gain is not within specifications, an idle fuel-air mixture adjustment is necessary. Adjust idle mixture according to reset RPM
specification. Remove limiter caps from carburetor idle mixture screws. Use Rotunda tool No. T75L-9500-A or equivalent to prevent screw
damage. To adjust idle mixture on vehicles equipped with tamper resistant screws, remove plug over mixture adjustment. Refer to Carburetor
Section for plug removal. If speed increase is lower than specification, lean the mixture without propane by turning the mixture screws clockwise.
To obtain an approximate setting, lean mixture while checking tachometer idle speed drop the number of RPM needed to approximately obtain the
speed gain reset specification. Reset curb idle to specification, check propane to the reset specification. Ensure to operate engine at 2500 RPM to
stabilize idle speed. Repeat idle mixture adjustment procedure and curb idle adjustment until correct reset propane RPM is reached. Proceed to
step 18 for all carburetors. If speed increase is higher than specification, richen mixture without propane by turning mixture screws
counterclockwise. To obtain an approximate setting, richen mixture while checking tachometer idle speed increase the number of RPM needed to
obtain an approximate speed gain setting. Reset curb idle speed to specification, check propane gain to the reset specification, and repeat idle
mixture adjustment procedure and curb idle adjustment until correct reset propane rpm gain is obtained. On all carburetors proceed to step 18.
17.
Speed drop test, note the following:
NOTE: Speed drop test is required with propane enrichment procedure whenever vehicles have a zero gain and a zero minimum gain
specification.
a.
While checking tachometer, adjust mixture screw clockwise.Note drop in engine speed.
b.
If the measured speed drop is equal to or drops off by more than the speed drop specification, return idle mixture screws to the position
before adjustment. Proceed to step 18 for all carburetors.
c.
If measured speed drop is less than specified minimum speed drop specification, leave mixture screws or venturi air bypass screw in the
adjusted position. Repeat curb idle adjustment and propane enrichment gain check procedure beginning at step 13. If within specification,
proceed to step 18.
18.
On all carburetors equipped with limiter caps, install new blue limiter caps in the maximum rich position. Ensure to use the right length caps.
19.
Check engine idle rpm and idle speed gain to ensure idle mixture screws were not disturbed during limiter installation. Correct if necessary.
20.
Switch engine "OFF" and remove propane enrichment test equipment. Install purge tube and fresh air duct as required. Remove plugs from fuel
evaporative purge signal vacuum hose, connect fuel evaporative purge valve return hose at engine and install air cleaner, if removed.
21.
Remove plug from parking brake vacuum hose and install hose. Connect all thermactor hoses. Remove test equipment and check all engine system
connections.
