Edelbrock 1905 - Manual (Page 4)

Page 4 of 6 Rev. 10/01 2001 Edelbrock Corporation
Brochure No. 63-0018
©
IDLE MIXTURE ADJUSTMENT
The Edelbrock Performer Q-Jet Carburetor for Thermo-Quad applications has conventional Idle Mixture Screws (IMS) that
provide a leaner Air/Fuel (A/F) ratio when turned clockwise and richer A/F ratio when turned counterclockwise. The idle
air flow is controlled by a conventional screw that opens the primary throttles. The following procedure should be used
to set the idle mixture and speed:
1. Fully warm engine and ensure choke is fully open.
2. Install air cleaner.
3. Set desired speed with the air screw.
4. Adjust the IMS on one side to get the maximum possible rpm or highest vacuum if you are using a manifold
vacuum gauge. Do not go rich beyond the maximum speed point.
5. If the procedure above changed the idle speed more than 40 rpm, then re-adjust the idle speed.
6. Adjust the opposite side of that in Step 4 to get maximum rpm or vacuum.
7. Reset the speed.
8. Carefully trim each IMS to again get the maximum idle rpm or manifold vacuum.
9. Go leaner just enough to get a 20 rpm drop in speed.
10. Reset the speed to the desired rpm.
11. This is a Lean-Best Idle Set. Setting richer than this will not improve idle quality or performance, but could
cause higher hydrocarbon emissions and tend to foul spark plugs.
12. Emission legal carburetor #1905 is supplied with tamper-resistant protective metal caps for idle mixture
screw wells. These covers should be installed following completion of final idle mixture adjustments.
NOTE: Use idle mixture adjustment tool K&D #2776 or equivalent.
WINTER FUEL IDLE SETS
During the winter months (in most parts of the country), the local fuel will be a "winter" blend that is very volatile, as an
assist to cold-engine starting and drivability during warm-up. However, the high volatility has the disadvantage of allowing
excessive vaporization of the fuel if the vehicle is operated in a heated area such as a garage. This can result in problems
in the idle-set procedures since the carburetor's internal vents will allow this excess vapor to be drawn into the throats
and enriches the mixture. The idle will be erratic and not seem to be able to hold a set. To resolve this problem, it is
advisable to perform the final settings outdoors after the vehicle has been stabilized with a drive of several miles.
EDELBROCK Q-JET REBUILD KITS
The Edelbrock Performer Q-Jet Carburetor for Thermo-Quad applications can be rebuilt with the following rebuild kits:
Carburetor Part Number Rebuild Kit Part Number
#1905 #1921
REPLACEMENT FUEL FILTERS
The Edelbrock Performer Q-Jet Carburetor for Thermo-Quad applications has a replaceable fuel filter element behind the
Fuel Inlet Nut. Replacement filters are available as follows:
Carburetor Part Number Fuel Filter Part Number
#1905 #1927
IMPORTANT INFORMATION ABOUT YOUR WARRANTY
If you have any problems with installation or performance, do not return to the retailer. Retailer is not authorized to
perform Warranty Service. Instead, call the Edelbrock Carburetor Tech Hotline at 800-416-8628 from 7am - 5:00pm PST
on weekdays. All returns must be accompanied by the original purchase receipt. The warranty period is 90 days for new
carburetors and 30 days for "as-new" (remanufactured) carburetors.
SPECIAL NOTICE
Edelbrock Performer Q-Jet Carburetor for Thermo-Quad Applications is legal for street use on pollution-
controlled motor vehicles in all 50 states. To assist you with emissions equipment certification, we have included a
fan shroud decal to help testing personnel verify that the carburetor is a legal replacement part for 1985 & earlier Chrysler
360, 400 and 440-equipped vehicles. The adhesive-backed decal should be affixed to your fan shroud next to the existing
emission and engine specification decal. Do not cover your original equipment specification decal with the Edelbrock
Performer Q-Jet Carburetor decal.