Generator Reviews

Diesel Generators Starting Problems, Fixing and Solutions

Is your diesel generator not starting? Don’t worry; this review on fixing diesel generators starting problems will give an insight on all you should know about the diesel generator and its common starting issues also diesel generators troubleshooting guide you should know to get the best out of your diesel Genset.

The diesel generator is a very good and reliable backup source of power supply especially when it is needed most where the power from the grid isn’t forthcoming.

ALSO READ: Is your gasoline generator giving you some problem? See our review on “How to fix gasoline generators hard starting issues“.

To know and read your diesel generator troubleshooting guide is necessary as it can become frustrating when you try to use your diesel generator and it refuses to start at all, let alone power your items. Well, these problems can arise from diverse problems and you just have to see which problem it is to rectify it.

Review on Diesel Generators Starting Problems, Fixing and Solutions

The Common Causes of Diesel Generators Starting Failure

  • The Dry, cracking and otherwise bad belts of DG can cause failure
  • Dead Batteries (Batteries not charged)
  • Block heater wear and tear
  • When there is low coolant, no coolant or lack of oil, it causes problem like overheating, over crank, cracked heads, broken pistons, catastrophic engine failure of the diesel generator.
  • No fuel (Lack of fuel), bad fuel, sludge in the fuel tank or lines cause failure.
  • When there is burnt components on the boards, electrical components, stepper motors, transfer coils, ice cube relays result to a problem in your diesel generator.
  • Also damages caused by weather and pest’s causes’ failure.

Things to check when carrying out scheduled maintenance on Diesel Generators

  • Full exterior and interior inspection
  • Cables and connections
  • Checking for worn parts and upgrading the components
  • Checking all fluid levels
  • Changing fuel, oil, air and coolant filters
  • Checking control panel readings and indicators
  • Load bank testing and regular exercise
  • Changing spark plugs
  • Check for leakage

Solutions for Fixing Diesel Generators Failure and Starting problems

What’s the good news know about the solutions for fixing the diesel generator sets! The good news here is that you can do-it-yourself (DIY) and you might not necessarily need an expert to handle it or a generator mechanic to help you in the process.

The first thing to do to fix diesel generators starting problems (issues) is identifying the cause of the problems. The immediate or known causes of starting problems of a Diesel generator sets are:

  • Fuel system failure
  • Electric starting system failure
  • Insufficient compression pressure in the cylinder
  • Low ambient temperature
  • Other factors

Now, after identifying the problem it will easy to fix the problem starting with the

1. Fuel System Failure

Fuel system failure occurs when the diesel generator fails to start normally, so they might be air in the fuel system, there’s fuel line obstruction, there might be fuel filter clogging, the handle position of fuel injection pump is not correctly placed, there’s a fuel injector problem or the oil supply has a problem.

To rectify the problem associated with fuel system failure is to do the following:

For Oil Supply Problem

Check to know if the oil inlet pipe is leaking to fix it but if not check the filter screen on the oil inlet pipe connector is blocked to unblock it.

The oil transfer pump needs to supply oil before a diesel generator can start or else it will give a starting problem.

Fuel Injector Problem

You need to be sure that your fuel injection is atomized but if not then the solution to fixing this is for you to remove the fuel injector and connect it to the high pressure oil pump and pry the fuel injection pump plunger spring, then observe the spray condition. If all else fails you can wash the injection pump.

The Air in the Fuel System Problem

To fix this problem, first check that the fuel oil pipe connector isn’t loose, and then make sure that the air is cleared from the fuel system.

You can loosen the bleed screw bolt on the diesel filter, then use the manual oil pump to pump the fuel until the air bubble is out and gone.

The Fuel Line Obstruction Problem

The solution is to check the pipeline and be sure it is very smooth for easy fuel passage. If not, ensure you clear it.

The Fuel Filter Clogging Problem

To fix this problem when occur on your diesel generator, just clean the filter or replace the filter element.

The handle Position Problem

The solution for this handle position problem is to push to no-load when starting the diesel generator set. The normal rotation speed should be about 700-900r/min.

2. Electric Starting System Failure

This is another major problem that can hinder the diesel generator from starting and it will make starting fails severally.

This problem can be because of battery power shortage or circuit wiring error or poor contact. These two problems can be rectify via these ways below:

For Battery Power Shortage

Use a battery with enough power and increase the battery to use in parallel. You can as well replace the start up battery with a new one when it is necessary.

Circuit Wiring Error

With this just check to be sure the wiring is correct and reliable too before starting your diesel generator.

3. Insufficient Compression Pressure in the Cylinder

This is one of the major problems that give starting problem to a diesel generator. This can happen when the cylinder is insufficient and maybe the fuel injection is normal but doesn’t catch fire or they might seem to be fuel oil inside the exhaust pipe.

So if there this is excess in the area of the piston, ring and cylinder liner or there’s valve leakage and maybe the combustion chamber volume is too large, the following solution can be adopted to get the diesel generators starting without further issues:

The problem of excessive wear of piston ring and cylinder line

You can fix this problem by replacing the piston and ring; again you can as well replace the cylinder liner according to the wear condition.

For the valve leakage problem

You will need to check the following; the valve clearance, the valve spring, same with the sealing of the valve seal and guide. If there are not in good condition, you might need to replace them as well to have a good working diesel generator.

The combustion chamber problem

If the combustion chamber volume is too large, you should first check if the piston belongs to the model of the diesel generator. If necessary, you can go further to measure the combustion chamber volume.

4. The Ambient Temperature is Low

Diesel engines are more prone to cylinder accidents at either 100 water temperature or high temperature. So the generator will stop working when the coolant exceeds 95 degrees.

The water temperature of a diesel generator set should be about 80 degrees while the maximum temperature shouldn’t exceed 95 degrees.

So to fix the problem of low ambient temperature on a diesel generators, which is according to the actual ambient temperature, the corresponding low temperature measures should be adopted.

5. Other factors

Other minor factors that might arise to give diesel generator starting problems are lack of maintenance or lack of operational knowledge.

So to fix this problem try to have periodic maintenance routine and update your knowledge on the little things that needs to be done on your diesel generator to keep it functional at all times.

This will not only prolong the lifespan of your diesel generating set but enable it to be efficient when once you need to use it.


There you have them, the do-it-yourself solution for difficult starting of your diesel generator. You will find these tips very useful anytime you cannot start your diesel generating set.

Just check out the problem using this guide and you will be on your way in kick-starting your diesel generator without any hiccups.

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