Some owners of carburetor cars are accustomed to thinking of the carburetor as a rather simple device, although the carburetor is a group of systems that work in conjunction with each other. Failure of any component results in malfunctions in the carburetor, so these malfunctions should be corrected immediately. One of these components is the carburetor accelerator pump. Many car owners are not even aware of the existence of such a unit.
Carburetor accelerator pump device
An accelerator pump is one of the carburetor components that supplies the fuel mixture when the throttle is open. This unit operates regardless of the air passing through the diffusers. During sudden acceleration, the carburetor is unable to supply the required amount of fuel to the cylinders. To neutralize this effect, an accelerator pump is needed. Its purpose is to speed up the supply of fuel to the cylinders.
This device ensures uninterrupted fuel supply during acceleration. At the same time, the acceleration of the car becomes sharper and smoother. Carburetor accelerator pump design:
- accelerator pump diaphragm (together with its head);
- drive lever;
- suction valve;
- fist on the throttle axis;
- carburetor accelerator pump discharge valve;
- spray;
- damping springs and suction stroke springs.
The principle of operation of the carburetor accelerator pump
The diaphragm (membrane) is connected to the fist through a lever that is located on the throttle valve. When the valve is closed, fuel flows freely into the cavity, the suction valve opens it up. When the damper is open, the valve, on the contrary, prevents fuel from flowing out of the cavity. Air does not enter this cavity under any circumstances. Gasoline is also supplied to the sprayers through this valve. Suction occurs under the action of the spring, and discharge occurs due to the mechanical action of the lever on the diaphragm head. The accelerator pump nozzles are responsible for supplying fuel to the nozzles. One accelerator pump nozzle is routed to each carburetor chamber. The jets are installed on the same platform as the discharge valve. To gain access to the jets, you need to gain access to the carburetor chambers.
How to check the accelerator pump for malfunctions
It is necessary to check the stability of the accelerator pump so that the carburetor works flawlessly. In order to prepare for the test, you should pump gasoline into the carburetor by hand and remove the top carburetor cover.
The verification scheme itself is not complicated. The throttle lever is turned manually by acting on the pump lever. During this procedure, fuel should spray out from the nozzles in streams, without touching any walls, but simply falling to the bottom of the intake well. If the streams are weak or crooked, then the jets, channels and nozzles need cleaning and adjustment. To accurately determine the stability of the accelerator pump, it is necessary to measure the amount of gasoline sprayed during 10 injection phases. To do this, you need to remove the carburetor and, after manually performing the injection procedure ten times, measure the amount of gasoline using a ten-cc syringe. The volume should range from 5.25 to 8.75 milliliters. If the volume does not fall within these parameters, it means that the accelerator pump is not working correctly or is faulty.
If the accelerator pump is faulty, when you sharply press the gas pedal, dips will be clearly felt, both while driving and at idle.
What brands and models of cars were installed on?
C were installed not only on VAZs. Other automakers also actively used them for their cars.
Table: modifications and applicability of Solex carburetors
| Modification | Applicability | Engine capacity, cm 3 | Notes |
| DAAZ-2108–1107010 | VAZ 2108, 2109 | 1,3 | |
| DAAZ-21081–1107010 | VAZ 21081, 21091, ZAZ 1102 | 1,1 | |
| DAAZ-21083–1107010 | VAZ 21083, 21093, 21099 | 1,5 | |
| DAAZ-21083–1107010–31 | VAZ 2108, 2109, 2110, 2111 | 1,5 | Has a semi-automatic starting device |
| DAAZ-21083–1107010–35 | VAZ 2108, 2109, 2110, 2111 | 1,5 | Has a two-level semi-automatic starting device (winter/summer) |
| DAAZ-21083–1107010–62 | VAZ 2109, 2115 | 1,5 | Has an electronic device for controlling the composition of the combustible mixture |
| DAAZ-21083–1107010–05 | VAZ 2109 | 1,5 | |
| DAAZ-21412–1107010, DAAZ-21412–1107010–30 | AZLK 2141, 2141–23 | 1,5/1,8 | |
| DAAZ-1111–1107010 | VAZ 1111, 11113 "Oka" | 0,65/0,75 | |
| DAAZ-21051–1107010 | VAZ 2103, 2105 | 1,5 | |
| DAAZ-21053–1107010 | VAZ 21074, 21061 | 1,6 | |
| DAAZ-21051–1107010–30 | VAZ 2104, 2105 | 1,3 | |
| DAAZ-21053–1107010–62 | VAZ 2107, 21072, 21074 | 1,3/1,5/1,6 | |
| DAAZ-21073–1107010 | VAZ 2121, 21213 "Niva" | 1,6/1,7 |
Checking and subsequent repair of the accelerator pump of the DAAZ Ozone carburetor
Before starting the test, manually pump gasoline into the float chamber and remove the carburetor cover.
The check should begin with the pump itself. By pressing the throttle drive lever, watch the stream of fuel from the nozzle. Ideally, it should be smooth and not touch the walls and axis of the damper. The timed injection should last 1-2 seconds. Problems with operation:
- The stream is weak and crooked. This means you need to clean the channels, atomizer, jets and valves;
- The injection lasts more than two seconds. This indicates a clogged bypass valve;
- Fuel got onto the hull. The diaphragm needs to be replaced or the cap needs to be secured.
Checking the DAAZ Ozone carburetor nozzles
To check the atomizer, you need to unscrew it from the housing. After unscrewing, press the damper lever. If a powerful stream flows from the hole, then the problem is in the sprayer or discharge valve. The nozzle of the sprayer can be easily cleaned with a wire, and the valve needs to be washed and blown out. The working sprayer should have a ball that makes a rattling noise when shaken.
Supply channels UN
If gasoline does not spray out of the hole when you press the throttle lever, the supply channels of the accelerator pump may be clogged. To clean them, you need to remove the diaphragm and clean the fuel supply channels with wire. They should be washed with carburetor cleaning fluid and blown out.
How to check the bypass channel together with the UN jet
When you press the throttle lever, you need to monitor the flow of gasoline into the float chamber. If the stream is not visible and the seething is not even noticeable, then the channel needs to be cleaned. At the same time, you need to wash the bypass jet. Everything is washed in the same way as other channels and blown out with compressed air.
What is the difference between modifications 21081 and 21083
If you compare the two main modifications of Solex carburetors (21081 and 21083), used on front-wheel drive Sputniks and Samaras, then visually you will not find any differences between them. The difference exists only in the operating parameters of some of their elements.
Table: comparison of basic calibration data for Solex carburetors 21081 and 21083
| 21081 | 21083 | |||
| For 1st camera | For 2nd camera | For 1st camera | For 2nd camera | |
| Mixing chamber diameter, mm | 32 | 32 | ||
| Diffuser diameter, mm | 21 | 23 | 21 | 23 |
| Air jet of the main dosing system | 165 | 135 | 155 | 125 |
| Fuel jet of the main metering system | 95 | 97,5 | 95 | 97,5 |
| Idle air jet | 170 | 170 | ||
| Idle fuel jet | 39–44 | 39–44 | ||
| Air jet of the second chamber transition system | 120 | 120 | ||
| Fuel nozzle of the second chamber transition system | 50 | 50 | ||
| Economizer fuel jet | 40 | 40 | ||
| Accelerator pump cam number (size) | 4 | 7 | ||
| Throttle valve starting gap, mm | 1,0 | 1,1 | ||
| Air damper starting gap, mm | 2,7±0,2 | 2,5±0,2 | ||
| Needle valve hole diameter, mm | 1,8 | 1,8 | ||
| Vacuum regulator hole diameter, mm | 1,2 | 1,2 | ||
How to check and repair the accelerator pump of a Solex carburetor
Preparation for testing the Solex accelerator pump is no different from preparing the accelerator pump for a DAAZ Ozone carburetor. In the same way, fuel is pumped into the carburetor and the top carburetor cover is removed.
Checking the operation of the Solex accelerator pump
Turn the throttle lever and watch how injection occurs in the carburetor. The jets from the sprayers should be smooth, strong, free of breaks, and not touch the walls and axis of the throttle valve. The injection must last for at least two seconds.
If the stream is weak and crooked, then you should clean the channels, sprayer, jets and valves. If jets of fuel hit the chamber walls, you need to adjust the position of the spray nozzles using pliers.
Solex carburetor accelerator pump repair
Repairing the Solex accelerator pump, as in the case of the DAAZ system, must begin with repairing the nozzles. The sprayer is carefully removed using a screwdriver. You need to shake it immediately to check for the presence of a discharge valve ball. In domestically produced carburetors, there are known cases where the ball was forgotten to be installed at the manufacturer's plant. Usually, if no sounds are heard, then there is significant pollution. If you cannot clean the element, it should be replaced with a new one. During the cleaning process, both spouts must be thoroughly blown out with compressed air. If this procedure does not help, the spouts are soaked in a special solution for a couple of hours and the blowing is repeated. If this does not help, then a replacement is needed.
Accelerator pump valves and channels
If there is no strong jet, you need to clean all the valves and channels of the UN carburetor. They are cleaned with wire, followed by washing and blowing.
The hole from the sprayer is filled with acetone and cleaned with a toothpick. To clean the channel hole, you need to remove the spring and diaphragm. The hole itself is cleaned with thin wire and blown through. The float chamber also has a hole, which is cleaned in the same way.
During assembly, be sure to check the condition of the diaphragm. If there are abrasions or damage, it is replaced with a new one.
When the accelerator pump cover is put back on, you need to turn the pump lever all the way so that the diaphragm stretches. Only after this are the screws tightened.
Many people are afraid of the process of repairing the carburetor accelerator pump, but if you have too much time, you can do this procedure yourself, unless, of course, you are afraid of the monotonous cleaning process.
If you have any questions, leave them in the comments below the article. We or our visitors will be happy to answer them
Main types of jets and their selection
The industry produces 2 types of carburetor jets, which are included in each repair kit:
They are made for each camera of the device. The choice of jet depends on the cross-section of the large and small carburetor diffuser. Repair kits are produced differently - for each model and brand of car. The parts differ in hole diameter. How to adjust the correct operation of the engine - information necessary for every vehicle owner.
https://youtube.com/watch?v=9YsPr_IfCdo
Quite often, the Solex carburetor is installed on cars of other brands, with the most powerful engines. In this case, the machine will work intermittently, because the VAZ jets will not be able to do their job efficiently - due to the diameter being insufficient to supply the enriched mixture.
Often, car enthusiasts install a large fuel part for better acceleration and dynamic driving. In this case, one should not forget about the increase in fuel consumption. Also, increasing the diameter of the nozzle by several orders of magnitude will not always give a good result. The table can tell you how to choose jets.
If the engine capacity is 1.6 liters, you should not install a main jet from a powerful engine on it. If you are no longer satisfied with the acceleration of your car, you may need to look for another reason, for example:
- low compression level in one of the cylinders;
- the adjustment of the ignition system has gone wrong;
- one or more spark plugs are faulty;
- Replacement of high-voltage wires is required.
These are just some of the reasons and malfunctions, by eliminating which you will get a fast car again. Car enthusiasts have different opinions about altering jets, but most believe that it is not worth doing. Sometimes, those who like to save money install jets whose sizes are smaller than the recommended ones. In this case, you get an economical, but very weak car that will take a very long time to accelerate. Ozone carburetor jets should not be installed in a Ford carburetor. They should be on the classic Zhiguli.
