Installation diagram of the injection pump for the YaMZ-238 engine. Pump pump Yamz 238 adjustment

That's the point. I work on a small locomotive with a YaMZ 238 engine. Without a turbine. We have many different ones. We recently received this one from conservation from another city to replace our broken one. We replaced both head gaskets because the system was airborne, the engine was boiling and the heater was not heating up due to the plugs. But it's not that. Not going! I mean, it doesn’t pull well. It starts up great. It doesn’t smoke. There’s the smell of unburnt diesel fuel, etc. No. My partner thinks that he eats a little more than usual. What's the question. While opening the engine, we realized that the wear was minimal, and the valves were adjusted. The air filter is not clogged. WHY doesn't it pull? ignition... ? Or should I still try to Crank up the pump? Who's familiar with this? how to do this and what bolts to turn there? I'M REALLY LOOKING FORWARD!

Injection pump device YaMZ-238

To ensure correct and productive operation of the power unit, fuel must be constantly supplied to its cylinders.
One of the main components of the working mixture transportation and injection system is the high-pressure fuel pump. Heavy-duty MAZ and KRAZ vehicles have a YaMZ-238 injection pump, which is distinguished by its reliability and high performance. But to ensure the correct fuel supply process, it requires adjustment.

Fuel supply system design

The design of the fuel supply system for the power unit consists of the following elements:

• injection pump;
• mixture formation corrector;
• high pressure tubes;
• main fuel lines;
• speed controller;
• filter elements;
• fuel pump;
• injectors.

Let us briefly describe the principle of operation of the fuel supply system. The fuel pump supplies it to the injection pump through coarse and fine filters. In accordance with the operating mode of the power unit, the injection pump injects the working mixture into the engine cylinders through injectors. The fuel system circuit is designed in such a way that excess mixture flows back into the tank through the main pipes.

Operating principle of fuel injection pump YaMZ-238

The pump has compact dimensions and is located in the engine compartment on the plane of the power unit, between the rows of cylinders. The injection pump has eight sections (one for each cylinder) and a gear drive. The fuel pump, depending on the engine power, comes in several types, each of which has its own design features and adjustment method.

The operating principle of the injection pump is not complicated, but has certain nuances. To create primary pressure, the system is equipped with a fuel pump, which supplies the working mixture to the fuel injection pump chambers, with the plunger in the lower position.

As soon as the plunger begins forward movement, upon reaching a certain position, it opens the discharge valve to further supply the mixture and inject it. The pressure in the fuel chamber increases due to the upward movement of the plunger.

When the maximum pressure is reached, the nozzle needle rises and the working mixture begins to flow into the cylinder. As soon as the plunger reaches its final upper position, the pressure of the working mixture in the discharge circuit will begin to decrease sharply. As a result, the injector needle will return to its initial position and fuel injection will stop.

One of the most common fuel injection pump malfunctions is a worn oil seal. In this case, the repair is not difficult and you can do it yourself. On the Internet you can find a video with a detailed description of the working process.

Adjusting the injection pump YaMZ-238

All performance indicators of the power unit depend on the correct adjustment of the pump: power, productivity, efficiency, operational life. Therefore, all stages of the adjustment process are extremely important and should be performed only by highly professional specialists using technological equipment.

Often, the fuel injection pump of the brand being described is adjusted at the following stands:

1. NTs-108 (Czechoslovakia).
2. Star-12.
3. Minor-8.

Adjustment of fuel injection pump parameters on a bench is necessarily carried out with injectors that will work with it on the engine. The order of work during adjustments is very important, since violation of the sequence of activities performed is the cause of incorrect operation of the pump in the future.

At the initial stage, the fuel supply between the pump sections is adjusted, after which the optimal injection value is adjusted. The supply of the working mixture is adjusted using a momentoscope, while the automatic advance clutch must be removed. The uniformity and amount of mixture supply to the fuel injection pump sections is regulated using a cam shaft. The final stage of setup is to lubricate all interacting elements.

Connection diagram

When installing the injection pump on the power unit, you must pay attention to ensure that the marks of the drive coupling half and the injection advance are at the same level. It is necessary to correctly set all axial clearances between the cams and the ends of the couplings and coupling halves before finally tightening the mounting bolts. The size of the gaps should not exceed 0.3 mm. After installing the adjusted fuel injection pump on the engine, the fuel supply lines should be connected.

The main feature of the high-pressure fuel pump connection diagram is the correct sequence of connecting the fuel lines and injectors.

Adjustment data for injection pump 805.7-50 Engine YaMZ-238ND5 - injection pump - Motorist's Handbook

How to add fuel to Yamz 238

That's the point. I work on a small locomotive with a YaMZ 238 engine. Without a turbine. We have many different ones. We recently received this one from conservation from another city to replace our broken one. We replaced both head gaskets because the system was airborne, the engine was boiling and the heater was not heating up due to the plugs. But it's not that. Not going! I mean, it doesn’t pull well. It starts up great. It doesn’t smoke. There’s the smell of unburnt diesel fuel, etc. No. My partner thinks that he eats a little more than usual. What's the question. While opening the engine, we realized that the wear was minimal, and the valves were adjusted. The air filter is not clogged. WHY doesn't it pull? ignition... ? Or should I still try to Crank up the pump? Who's familiar with this? how to do this and what bolts to turn there? I'M REALLY LOOKING FORWARD!

see also

Comments 43

Try ignition a little earlier and add fuel.

Here truck drivers advise where and what screws to turn

I am posting a video about leaky gaskets under the heads...

it reacts like this. when there is not enough fuel, the thrust of the gas is sharp until the end of the smoke, either there is no smoke, or the gray one turned the bolt half a turn, the gas was blown by a ball of black smoke, and then the normal exhaust means it reacted, and if not, it means that in the inside under the cover it is on 6 or 4 bolts, the thrust is turned out and the bolt it does not limit it, then you need to twist it and then use the bolt in the opposite direction.

from the rear on the turbine side.

I work at KrAZ myself.

In the third picture, unscrew bolt 19 completely, and then adjust the fuel supply. Open or close.

Don't think that I'm stupid! :) BOLT!) unscrew completely or 19? Should I adjust 10 or 19?

In short, I adjusted it myself like this: one bolt in front on the side of the coupling near the check valve. It regulates the stroke of the rack and is tightened during break-in (the so-called virgin), so it must be turned out completely. Now you look at the equipment from the back. There is a large bolt in the middle - it regulates idle, set it as it should. Then look below, at the bottom right there is a small bolt with a nut set to 10. This is a power limit. You unscrew it completely. If after that it starts smoking a lot black, it means there is a lot of fuel, open the lid and see two more bolts : larger and smaller. Don’t touch the larger one, the smaller one regulates the fuel supply. You need to turn it a quarter turn. clockwise - you decrease it, counterclockwise - you add it. Spun it, close the lid, work it, look for the smoke, if you don’t like it, turn it again and you won’t like it until you like it. When you suddenly add load or when moving under load, the engine should smoke slightly black, but not thickly and not completely without smoke. This is what a very good equipment technician taught me, who repaired it for me. I adjusted it, I answer you: the machine pulls at 5+ and the consumption is very low compared to other KrAZ trucks in our database. I carry a 60-ton trawl, believe me, all this is important. If I didn't pull well, I simply wouldn't be able to work. I also adjusted the ignition. This whole thing about 19 degrees is complete crap. No matter how many times I tried to set it according to the manual, well, it doesn’t work as it should. You adjust it several times by ear. It growls, smokes and works hard - early, it’s dull and quiet it works later. You find the golden mean at random and rejoice. Experience on the same machine is nine years, I think it’s enough to study.

Thank you! Informative! We usually do the ignition ourselves by eye. I understand about the pump. I’ll try it!

Don’t forget about non-injection pump malfunctions (see above)

Bolt 10 must be unscrewed completely, this is the rack travel limiter; by the way, it is tightened during conservation and break-in. Sometimes it tightens spontaneously; if you want to regulate the fuel supply, you open the back cover and the adjusting bolt is on the top left. To add, unscrew, decrease, tighten. Unscrew literally a quarter turn and try while driving. Otherwise, for non-injection pump reasons, there could be a banal clogging of the fuel filter(s), a clogged fuel intake strainer in the tank, a burst spring in the pump, ignition.

Installation sequence of the MAZ high pressure fuel pump

You can install the fuel injection pump for YaMZ engines yourself. First you need to install the driven coupling half, securely fixing the part. Next, install the flange. Check that the protrusion is always on the left.

The YaMZ injection pump drive is installed on a motor with a damper coupling. Secure the connection with bolts, adjusting the flatness of the strips. The pump is placed vertically on the engine cylinders.

Maintain a bolt fixing torque of no more than 4 N*m. Screw in the fasteners evenly to avoid blocking the pump.

The injection pump sections of YaMZ engines are connected to the injectors of the fuel lines. They follow a certain order. Then the injection advance angle is adjusted.

Be sure to check the oil in the YaMZ injection pump drive design and top it up to the required level. Start the vehicle engine. Adjust the lower idle speed according to the following scheme:

The adjustment is carried out until slight vibrations of the crankshaft occur. Having completed the process, the limit bolt must be locked.

The idle speed is regulated not only during the use and repair of YaMZ fuel injection pumps. The new motor also needs to be checked. It is forbidden to violate the factory settings.

Therefore, it is recommended to check the unit on a special stand.

If you need to buy a new pump, purchase YaMZ fuel injection pumps at competitive prices from trusted dealers. On our website you will find everything you need to effectively repair your car.

Injection angle calibration

To correctly determine the angle, there are 2 control clearances on the wheel case, and on the disk there are angle reference points at 2 points.

The bottom value is indicated by numbers, and those on the side are indicated by letters.

• A – 20°;
• B – 15°;
• B – 10°;
• G – 5°.

To install the YaMZ 238 ignition, you need to open the openings on the rotary disk case. Next, you should rotate the crankshaft of the internal combustion engine until the strokes on the pulley connect with the body of the timing gears. You can also pay attention to the convergence of the strokes on the flywheel with the reference point.

Reference! During calibration, the obtained indicators must coincide with the regulated ones - VT (6°–7°). And all manipulations are carried out with closed pistons in the first cylinder.

Angle calibration must be carried out until the value “A” coincides with o. The first is at the end, and the second is at the pointer.

Consequences of incorrect adjustment

All stages of work on adjusting the injection angle should be done only if the master has a sufficient level of competence. The necessary tools must also be available and in order. Otherwise, no one will guarantee that the procedure will be performed correctly. An incorrectly performed operation can cause serious problems in the future.

Any complex repair of a heavy truck without the appropriate competence may not only fail to solve the problem, but also lead to irreversible changes.

Make sure there is no early or late ignition. In the first case, the driver is faced with increased engine harshness, unpleasant ringing, and the appearance of white smoke. Frightening signs, their elimination lies in the correct adjustment of the ignition.

It is better to do this at a heavy truck service station. Otherwise, an incorrectly carried out procedure will become a test for the heavy loader and the driver.

Experienced drivers intuitively sense when adjustments to the ignition system are required. Even seasoned truck drivers are not always able to perform a complex procedure on their own. For this they need the help of specialized centers.

Beginners in driving heavy trucks are initially recommended to regularly carry out a technical inspection of the vehicle. Mechanics will tell you when ignition adjustment is required and promptly identify other serious problems with the vehicle. The service life of the vehicle is increased.

A series of steps to adjust the injection angle

To carry out proper calibration of the UOVT, a number of manipulations are performed.

• Evaluate the tightness of the fit of the YaMZ 238 ignition timing clutch, then tighten the screw of the terminal shaft.
• Unscrew the 2 screws of the clamping unit. Oval openings will help with this. On the damper coupling, connect o and “B”.
• Attach the screws to the drive.
• Carry out an analysis in the area where the plates are fixed. The permitted deviation of the plate package from the norm is within ±1 mm.
• Rotate the crankshaft and evaluate whether the OVT is set correctly. The permitted deviation from the norm is within 1° of crankshaft rotation or one division.
• Check the oil level in the OVT clamping unit. You should also check the degree of wear of the YaMZ 238 injection pump oil seal.
• Finally, check how the fuel injection angle is set.

Advice! To ensure that the angle is correct, you need to install the clamping unit with the opening in the upper position and remove the covers. When the unit rotates quietly at 70°, lubricant should flow from the opening. Then screw the lids on.

Adjustment data for injection pump 804.7-21 Engine YaMZ-238N - injection pump - Motorist's Handbook

How to set the angle on the YaMZ-238 internal combustion engine

The setting of the injection angle is influenced by the characteristics of each clutch separately, as well as the selection of the advance clamping unit at the front end of the body with numbers 18 and 20.

The correct angle calibration looks like this:

• remove the high pressure hose from the nozzle of the first pump cell;
• clamp the torque meter on the same pipe;
• remove the fuel injection pump body cover to bleed air. This will be required in order to pump fuel into the internal combustion engine power supply systems in the future;
• pump until the fuel used stops foaming, then close the lid tightly;
• now you need to make sure that the fuel supply by the controller bracket is active, then start turning the internal combustion engine shaft from left to right until fuel appears in the glass hose of the torque meter;
• While continuing to rotate the shaft, it is necessary to control the fuel in the glass compartment of the device.

Advice! If necessary, you should use the YaMZ 238 injection pump repair kit to set the angle as accurately as possible.

Connection diagram

When installing the injection pump on the power unit, you must pay attention to ensure that the marks of the drive coupling half and the injection advance are at the same level. It is necessary to correctly set all axial clearances between the cams and the ends of the couplings and coupling halves before finally tightening the mounting bolts. The size of the gaps should not exceed 0.3 mm. After installing the adjusted fuel injection pump on the engine, the fuel supply lines should be connected.

The main feature of the high-pressure fuel pump connection diagram is the correct sequence of connecting the fuel lines and injectors.

The first stage of fuel pump repair, adjustment of the YaMZ 238 injection pump, must be performed using special equipment. Here it is important to identify possible causes of failure and determine the degree of wear of parts.

High-quality adjustment affects the economy and efficiency of diesel engines. Affects the operation of the fuel system.

Fuel flow analysis

You must be able to correctly assess fuel movement if you plan to set the ignition yourself.

When rotating the shaft:

• the fuel in the compartment moves;
• the strokes on the flywheel case are aligned with the mark. Its value matches the number on the OVT coupling;
• the mark on the shaft pulley coincides with a mark with a similar number on the body of the gears.

If there is no alignment of strokes when starting the movement of the fuel, it is recommended to carry out the following manipulations:

• remove the fixing screws;
• twist the shaft coupling of the YaMZ 238 turbo engine on the edge in the opposite direction of rotation;
• secure all fasteners;
• re-evaluate the injection angle.

If, when starting fuel movement, the strokes have passed the required mark, do the following:

• along the thread of the edge it is necessary to rotate the coupling half of the internal combustion engine shaft;
• move the clutch 1 notch relative to its edge, which equates to 4 strokes on the disc or body of the timing gears.

Advice! As soon as all the manipulations are completed, it is recommended to change the location of the divisions on the coupling half of the YaMZ 238 injection pump drive shaft and its edge.

How to check the accuracy of the fuel injection value

The discrepancy in readings should not exceed 1°. To check the accuracy of setting the feed advance angle on the YaMZ-238 you need to:

• Place the fixing element from the recess on the flywheel without securing it in the upper position.
• Rotate the crankshaft one and a half turns.
• Rotate the crankshaft moderately and observe the fuel in the glass chamber of the measuring device.

Engine YaMZ 238

When the fuel begins to move in the chamber, the marks on the rotary wheel casing should coincide with the digital value indicated on the end part of the OVT coupling. Or the notch on the crankshaft impeller should be opposite the mark with a similar number on the camshaft housing.

If at the beginning of the movement of fuel in the chamber the marks have not yet coincided, you need to unscrew the fastening bolts, then rotate the motor shaft coupling half on the flange in the opposite direction of torsion, tighten the fastening bolts back, and again check the position of the fuel injection advance angle.

The steps above must be performed with special equipment. If there is not enough experience, knowledge and material and technical base to correctly set the engine ignition and regulate the fuel injection pump, it is better to turn to professionals with this issue. Incorrectly installed fire protection equipment is the cause of serious, expensive and, often, irreparable breakdowns.