VAZ (Lada) 2101/2103/2106 1970 - 2006
Carburetor 21073, engine 1300, classic. Failure when starting off. Tz 1 = 107 w.zh 2 = 150, tl 2 = 115, w.w 2 = 135. Ganders tried double, single, the effect is the same. Cam 4. The replacement of the fuel jets in places helped, in the first 115 to the second 107. But it is possible to increase the consumption. Tell me how to remove the failure and minimize the expense?
You are sucking in air, the mixture is depleting, and that's the failure. By installing the first enlarged fuel nozzle, you made the mixture normal, but the fuel consumption will increase for sure. Most often, the carburetor jars, when installed - they are too zealous when tightening. With some kind of spray (Unisma, Carburetor Cleaner), sprinkle while the engine is running, on the joints of the carburetor. Where there will be a gap, your motor will change the rpm. The slot can also be at the junction of the intake manifold to the cylinder head. If the carburetor sole is bent, it must be corrected and polished, and it is imperative to insert new gaskets every time.
On the jets: 107 fuel in the first chamber for your volume is normal, if you want you can put 109. But no more. And for efficiency, in the second chamber, reduce the fuel, put 112 or even 109, but you will not accelerate to 200-hundred km / h, but there will be efficiency.
Physics cannot be fooled.
Since you are complaining about the moment when starting off, we do not touch the second camera (it is mainly for the track, there is a race, and maximum speed). When starting off, the first camera works, you have already experienced it - put an enlarged jet and the car worked as it should. Everything. I have already told you the rest. Most likely, you just haven't found this suction yet (there are a few more places that, for example, are visible from the side, from below, the throttle valve shaft produces a hole, there is also a hose on the VUT, which is connected to the intake manifold, there may even be a manifold with a crack).
One friend also resisted for a long time (he has a carburetor gazelle), shouts - I redid everything, revised everything, but still came to complain to the carburetor. The engine is on, it works intermittently, the carburetor is a brave man - as he started pouring gasoline from a bottle on the engine, and ... the engine started running smoothly - and there were cracks. The work of the master is afraid, and the friend has ceased to expose his me, I, and always consults if he doubts anything.
This article will focus on engine failures caused by the carburetor. Ignition problems are not covered here.
To define the terminology, let me explain that failure is understood as too earthy reaction of the engine to pressing the accelerator pedal, sometimes accompanied by a braking effect, i.e. when you press the pedal, and the engine, instead of instantly spinning up, the sleep, as it were, tries to stall, and then, jerking, comes to life.
A logical explanation for this unpleasant effect is a sharp depletion (or lack of enrichment) of the mixture prepared by carb in throttling modes.
More than half of all dip problems are associated with the carburetor Accelerator Pump (UP) system. Its task is to create a forced enrichment of the mixture, mechanically associated with pressing the gas pedal. Those. with the engine off, pressing the gas pedal will be accompanied by the injection of a portion of gasoline into the carbamide chambers (this is how inexperienced drivers fill in the candles when starting). All other karba systems work by discharging, i.e. depending on the suction force in the intake manifold. Turning on and off from the operation of certain carb systems is directly related to the position (angle of rotation) throttle valves... Like everything in this world is subject to the factor of time, so carb cannot instantly prepare the required mixture composition when throttling. For example, you abruptly, from scratch, press the gas into the floor, both dampers open, providing air a way into the intake manifold, and gasoline has not yet had time to flow through the channels of the carb, so you have a sharply lean mixture - the engine is trying to stall. To enrich the mixture at such moments, people came up with UN. And even smarter ones invented the injector :-))
You can check the operation of the UN by removing the air filter housing and, looking into the chambers, press the throttle cable with your hand. The trickles should spray from both dispensers (tubes, pots :-)) evenly, without touching the walls of the chambers and without interruptions.
1. If you open two dampers at once (press the gas all the way), then the duration of operation of the standard (35 and 40) UN d.b. about 2 seconds. If the capacity is clearly less, then check whether the cam of the UN drive has been wiped off the pusher leg. This groove can be eliminated by wrapping the leg with a thin sheet of sheet metal, for example. But usually this problem appears after a long run :-) Also check the length and correct installation of the spring under the diaphragm.
2. It is necessary to check the integrity of the diaphragm. At the slightest hint of cracks, change. Be sure to tighten the cap securely. The diaphragm stem should move freely in its seat.
3. If the diaphragm is intact, but the UN does not work (if there is gasoline in the float chambers, EU-but :-)) or does not spray the fuel correctly, then it is better to change the UN body with nozzles - a ball will probably jam inside and when the gas pedal is released under the diaphragm instead of gasoline air enters. On the case, be sure to use it. rubber sealing ring - if it is absent or wrinkled, when you press the gas, gasoline will flow down the walls of the 1st chamber, and when released, air will get under the diaphragm ...
You should be very careful when buying and installing a UN housing! First, the tubes must not rotate in the housing. They must sit tight, otherwise one day one of them may jump out, for example a small one, and get into the intake manifold, and maybe even further ... Sad! UN building d.b. not full of holes, otherwise there have been such cases :-). Secondly, before installing the UN in the carb, it is better to slightly spread the tubes in different directions, so that, clinging to the walls of the slot, they keep the UN body well from turning in the seat (the settings of the jets get confused). Thirdly, it is impossible to insert the UN body into the carb on a dry basis - you can damage the rubber ring. Therefore, before installing, I recommend sprinkling the body and the hole for it in the WD-40 carbide, for example.
4. Now the most interesting thing :-) Many people believe that it is possible to accurately direct the trickles of the UN without removing the carb - they are mistaken! Each trickle should fall exactly into the manifold at the smallest possible angle of rotation of each damper, bypassing the walls of the chambers (not only above the dampers, but also UNDER the dampers), the dampers themselves and the thermal insulation gasket under the carburetor! Therefore, it is necessary to direct the trickles on the removed carbet, looking at it from below and turning the axes of the dampers. If the eye is not trained yet or you do not "know by heart" the thickness of the gasket, then apply it to the bottom of the carb and hold it so that the holes for the studs are aligned (or simply insert these studs there). Don't forget to pour gasoline into the float chambers :-)
However, it is impossible to completely exclude the failures of only c with the help of UN, so people also invented transition systems (PS). There are two of them - at the first and second chambers. They are also triggered by vacuum when the dampers are opened. If you have a failure at the start from a standstill or on the move with a very light press on the gas pedal, then in addition to the UN, you need to check the operation of the PS of the 1st chamber. It is powered from the same channel as slot XX. You can try blowing out under pressure by removing the top of the carb and attaching the pump hose to the brass tube with a rubber ring protruding from the bottom. You can still sprinkle a carb cleaner there before that. However, this rarely helps and you need to remove and wash the carb :-(
If a small failure is observed with a small and smooth opening of the second chamber, then the corresponding PS is probably to blame for this. Without disassembling the carb, this problem can be tried to be eliminated similarly to the PS of the 1st chamber, by supplying the air pressure to the PS air nozzle of the 2nd chamber, which is located next to the econostat sprayer (a brass tube sticking out in the 2nd chamber). You will see a tiny hole on top there :-)
However, the dips in both cases can be influenced by the gap in the 2nd chamber. The damper should be slightly open only enough to exclude a puddle during the operation of the UN and nothing more! Many close it completely and bend the long UN spray from the 2nd chamber into the 1st ...
If you experience dips, or rather jerking, in the region of 2000 rpm and only slightly open the damper of the 1st chamber, then check if the green wiring of the EPHH is not permanently closed to the ground? If so, the valve will cut off the fuel supply through the XX and PS system of the 1st chamber as soon as the engine speed exceeds a certain threshold (usually 1900-2200 rpm) even if the gas pedal is not released. Here, when moving within these limits of revolutions at a damper angle that provides a discharge path only to the slots of the XX system and the PS of the 1st chamber, a constant on / off of the valve is observed. This is especially noticeable when driving at a leisurely pace in 4th gear.
It will never be superfluous to check the power mode economizer (EMR), namely the diaphragm, the absence of ball jamming, as well as the cleanliness of the vacuum take-off channel and jet. EMR enriches the mixture with increasing vacuum at the hole located under the flap of the first chamber.
The deepest dips are associated with clogging of the fuel jets of the main metering systems. Sometimes this effect suddenly comes and just as unexpectedly passes - this is due to the presence of a speck that can stick to the bottom of the nozzle, or with water in the float chambers. The same situation can occur when the needle valve gets stuck in the closed position. If dips occur at high speeds, then check the level in the float chamber and the performance of the gas pump.
A clogged gas tank vent tube and an econostat in a carb will likely lead to a loss of power rather than a failure.
Frequent problems when pressing the accelerator pedal carburetor engine are the so-called "dip", "jerk", "twitch" and "wobble".
Failure - this is when, when adding gas when starting off or during acceleration of the car, there is a sluggish operation of the engine, a slow increase in revolutions up to a deceleration lasting from half a second to several seconds.
Dash - the same dip, but shorter, up to half a second.
Twitching - a series of several jerks.
Rocking - several failures following one after another.
It is worth noting that before eliminating these malfunctions by changing the settings of the carburetor itself or disassembling it, you need to make sure that the reason lies precisely in it.
Is of great importance technical condition engine. Incorrect installation of the timing mechanism, wear camshaft, incorrect ignition, violation of compression in the cylinders: too low or unacceptably different in different cylinders. All this disrupts the normal operation of the engine, increases fuel consumption, and leads to clogging of the carburetor with deposits and resins.
It is also necessary to check the fuel supply system before the carburetor for blockages in the fine filter, the mesh filter of the fuel pump, in the fuel intake, the tightness of the fuel pump, as well as the ignition system. In the mode idle move or at low loads, the engine may work normally, but with an increase in load, disturbances in the fuel supply may appear.
We will assume that the ignition, gas distribution, cylinder and fuel supply systems are fully operational and the reason lies in the carburetor. Consider possible reasons the occurrence of dips and jerks of the Solex 21083 carburetor and how to eliminate them:
Starting failures
The outlet of the adapter is clogged.
Hole size can decrease over time due to deposits reducing fuel flow and lean mixture. For cleaning holes transition systems you will have to remove the carburetor, turn it over and clean it with a sharp stick or copper wire (you cannot clean the holes with anything harder than the carburetor material to avoid damaging the holes), rinse with acetone and blow.
Low fuel level in the float chamber. This situation makes the fuel mixture leaner. To find out the fuel level in the chamber, let the engine run for a while, then remove the upper half of the carburetor and measure the fuel level, for example, with a caliper, for Solex 21083 the level should be 29 ± 1 mm. Gasoline tends to evaporate quickly, so you need to remove the cover and take a measurement quickly.
The needle valve can jam, thereby disrupting the flow of fuel into the float chamber, you can return the needle to its place by slightly tapping, but it is better, of course, to replace it. If the fuel level is out of order, adjust the float mechanism.
Leaking tube supplying rarefaction to vacuum corrector of ignition... Check the tube for cracks, breaks, the tube should fit tightly on the corresponding fittings, replace the tube if necessary. 
Dips and jerks when the car is moving
Faulty accelerator pump, econostat or economizer.
The accelerator pump accounts for most of the failure problems. As the name implies, the function of the booster pump is to enrich the air-fuel mixture in all operating modes except idle.
The performance of the accelerator pump must be checked. To do this, remove air filter and watch the trickles of fuel from the nozzles in each of the chambers. When you press the pump lever, even streams will sprinkle from both spouts, and they should not fall on the walls of the chambers. Experienced craftsmen take out the nozzle of the elephant accelerator pump and bend its tubes so that the jets accurately fall into the gap between the chamber wall and the damper, and you should try to do this with the least possible opening of the damper. It is also necessary to take into account the thickness of the insulating pad under the carburetor, the jets should not touch its internal surfaces.
You can also recommend that you remake the spray in such a way that both nozzles go into the first chamber, keeping in mind the direction of the streams, they should not intersect with each other either. This adjustment can only be made on the removed carburetor. If no fuel jets are observed, visually inspect the booster pump. On carburetors with high mileage, it is possible to work out at the place where the flag adjoins the pusher of the accelerating pump, in which case parts will need to be replaced.
Check the diaphragm of the accelerating pump, if only in doubt about its integrity, replace it. Tighten the cover securely when assembling the pump.
However, there are failures, it is not only the accelerator pump that is to blame.
Econostat designed to enrich the fuel mixture while operating at maximum load. Since the econostat is a tube built into the carburetor body, its repair is reduced to flushing and purging; it will be more convenient to do this by removing the upper half of the carburetor.
- it is quite difficult to detect a malfunction of the motor associated with the economizer of power modes. But still check the diaphragm, ball for binding, jets and passages - they should be clean.
Clogged strainer carburetor or fine fuel filter... Unscrew the nut of the strainer, wash it, if necessary replace it with a new one. Change fuel filter fine cleaning.
The lower surface of the carburetor body is bent due to tight tightening of the intake manifold nuts. The flange that is attached to the intake manifold with four studs is unfortunately weak point carburetor. Over time, it bends, as a result of which a gap is formed into which additional air enters, depleting the mixture. This problem can be solved by leveling the lower surface of the carburetor. Correct the slight distortion by holding the carburetor in a vice. If the flange is bent strongly, then we correct the deformation first with a file, and then with an emery cloth. Do not forget to rinse the carburetor from sawdust afterwards and blow it with compressed air.
It is possible to determine what exactly the failure is connected with by the behavior of the engine in different modes.
A deep dip, sometimes before the engine stops, can be caused by a blockage in the main fuel jet.
Slight twitching when driving and sluggish acceleration - low level fuel in the float chamber.
Swaying, dips and jerks at high loads - violations in the fuel supply associated with fuel pump, blockage of the mesh filter, decrease in the throughput of the fine filter.
A dip that appears and disappears after 2-5 seconds indicates a problem with the accelerator pump.
