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CAT C-9 diesel engine can not be started what is the reason

Caterpillar 330C excavator configuration CAT C-9 diesel engine. The diesel engine uses hydraulic electronic unit injectors (HEUI) fuel injection and fuel injection quantity to achieve precise control, you can use the Electronic Technician (ET) on diesel engine fault diagnosis. In this paper, CAT C-9 diesel engine does not start Cause and Remedy for analysis.

CAT C-9 diesel engine fuel supply system

CAT C-9 diesel engine fuel supply system


1 electronic control system failure

(1) Battery

Diesel engine is started, if you can hear the starter solenoid valves “blah” sound and the starter gear and flywheel ring gear sound, but the engine does not start up speed, can be determined is the lack of battery power. You should check the power switch is bad, the battery posts and cables for loose or corroded, and with a multimeter to detect the battery voltage is within the normal range.

(2) starter

Turning the start switch, the starter does not operate, the battery and the start circuit is normal, measuring the ignition coil, the coil resistance is also maintained within the normal range, can be determined is the start there is a malfunction. At this point, the available multimeter test starter rotor and the stator coil resistance, in order to determine the fault location starter.

(3) electronic control system

If you installed a new diesel engine electronic control module (ECM), but not installed ECM Personalized unit, the machine will not start, while the electronic control module (ECM) will not work with Electronic Technician (ET) connection.

Hydraulic Electronic Unit Injector

(2) Fuel supply system failure

C-9 diesel engine fuel supply system consists of fuel pump, Hydraulic Electronic Unit Injectors (HEUI), electronic control module (ECM), high-pressure oil pump , fuel injector driving pressure control valve (IPA) and its sensors , etc. composition, shown in Figure 1 .

( 1 ) Low oil

Low oil pressure normal range 0.24 ~ 0.48MPa, if less than this pressure will make diesel engine does not start .

First check the fuel tank, if the fuel tank switch is turned on , there is enough diesel fuel tank , check the tank vent is blocked . If blocked, then check whether there is water or impurities in the oil pan .

Second, check the low pressure oil is smooth . Via hand pump for pumping tests , if pulled out when the button was no suction , and when you find it hard to press the button , indicating fuel pump and injector (HEUI) between the oil clogging the fuel filter should be checked clogging. If you find it hard to pull out when the button is obvious , but let go after the automatic back button , indicating that between tank and pump oil plug , check the tubing is blocked . If the pull-up, press the button, no normal pump oil resistance , indicating hand pump fails , you should check whether the pump outlet valve issuer or poor seal .

Finally check whether the low pressure oil mixed with air or moisture. Hand pumps pump oil, if there are air bubbles from the overflow vent plug hole , indicating that diesel fuel containing air , you should check whether the damaged pipeline , pipe joints are loose . If there is no damage or loose, should be carried out by stages deflated inspection. Method is: Loosen the oil pump on the joints , according to the hand pump, observe the discharge of oil , and if the foam endless row , indicating pump to the tank between the tank suction tubing or pipe rupture or loose connections ; if foam can drained , you should loosen the diesel filter output connector plug the exhaust or exhaust testing, inspection pipe joints for leaks. If a short time separated from the diesel fuel more water , then the water content in diesel excessive , replace standard diesel.

( 2 ) the high pressure

The high pressure of the normal operating pressure range 6 ~ 25MPa, if less than this pressure , the diesel engine will not start . You should check whether the high-pressure pipeline rupture or loose connections . If there is no leak , you should check whether the oil filter clogging . If these components are working properly, according to the following method to check :

First check the hydraulic electronic unit injectors (HEUI), the structure shown in Figure 2 . Its working principle is : the use of pressurized to 6 ~ 25MPa high-pressure oil to piston -powered , high-pressure oil acting on the injector inside the piston, the piston push the plunger down, so that the plunger produces higher injection pressure , fuel injector spray atomization to achieve the best results. Check the contents include: injector solenoid valve solenoid connector is loose, worn or broken wiring ; pressure oil leaks.

Secondly , connection of electronic Technician (ET), to detect whether there is fuel injection drive pressure fault code , if the fault code has recently been recorded, with the injector drive pressure problem. Injector drive time necessary to detect the pressure control valve (IAP) for export , if the output pressure is less than the minimum 6MPa, then the high pressure oil circuit is faulty.

3 intake and exhaust system failure

Intake and exhaust system causing the engine can not be started for reasons including: intake and exhaust pipes, air filter , intercooler clogging the cylinder charging efficiency decreased, resulting in difficulty in starting ; cylinder head gasket is damaged, piston ring wear overrun, cause poor sealing cylinder , the cylinder pressure is too low , causing difficulty in starting .

4 timing gear failure

Timing gear installation errors also cause the engine can not start. If the engine timing gear set installation errors , injection timing also will be an error , because the wrong time injection , diesel engine will not start. Shown in Figure 3 , when installing the timing gears , idler wheel 3 A timing mark on the crankshaft gear 4 to the cam gear 1 is a timing mark on

C-9 diesel engine timing gear mechanism

C-9 diesel engine timing gear mechanism

5 special environmental impact

( A ) low alpine region

Engine at low alpine region , the diesel volatility , flammability , and low-temperature fluidity is reduced, increasing the viscosity of lubricating oils and greases , decrease the battery performance , increasing the starting power , difficult to start . At this point , you can take the following measures: freezing measures taken on the diesel engine insulation, conditional dissecting loaded Jacket water heater ; starts, preheat cylinder diesel engine and use ether starting aid ; shutdown respond storage battery insulation , and appropriately increase the alternator voltage generated ; choose the appropriate grade of diesel fuel.

( 2 ) Plateau

Plateau Atmospheric pressure and low air density , temperature changes, the thin oxygen , resulting in reduced engine volumetric efficiency will lead to difficulty in starting diesel engines .

Should take the following measures: strengthening the intake system maintenance to minimize cylinder intake resistance , thereby improving the efficiency of the diesel engine inflatable ; choose low viscosity oil to reduce diesel engine starting resistance .

In short, there can not start when the engine failure, should insist on from simple to complex, from the outside and inside of the principle of timely, quickly and accurately find the point of failure and immediately removed. Technical requirements should be rational use of diesel engines, diesel strengthen routine maintenance work.


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