Here is the scenario:
Your mechanic or dealer has your Bobcat machine in the shop and they indicate the machine won’t start because of low rail pressure. The low rail pressure code is a result of a failed high pressure pump and/or failed fuel injectors.
You ask the mechanic what caused this? They say the failure is a result of fuel contamination (Could be dirt, water, metal, or anything else other than fuel. Learn more here: https://mydieselpro.com/what-is-fuel-contamination/) and they recommend dropping and cleaning the fuel tank and replacing every component in the fuel system.
You think this is outrageous and way too expensive and want to know why the entire fuel system needs to be replaced.
Here’s the answer: The fuel system on the D18/D24/D34 Doosan Bobcat engines is equipped with Delphi injectors which have a very small control valve in the injector which the tolerance is very tight. If anything other than clean diesel gets in this valve, it’ll either stick the valve (cause high fuel return and not fire the injector) or score the male and female portion of the valve (pictured below is a scorn valve) which will cause high return and misfire or very rough idle with lots of smoke.
Why is it important to replace the entire fuel system in case of a contamination event? If you just replace the injectors, whatever was circulating in every part of that fuel system will continue to circulate and either stick the control valve in 1 or more injectors right away (And you’ll think the dealer just sold you faulty injectors) or the machine will run great for a few minutes before starting to misfire then eventually shut off and then not restart due to low rail pressure
Replacing all components of the fuel system including installing the upgraded Bobcat Fuel Water Separator drastically reduces the chances of repeat failure of the fuel injectors. Simply flushing the various lines and fuel rail is in most cases not sufficient. It’ll save you from down time and the cost of replacing the injectors several times.
If you just installed 1 or more injectors and they don’t work or only worked for a very short period of time, most likely something went through them and failed the control valves
Diesel Pro offers complete contamination kits for the Bobcat D18/D24/D34 Doosan engine. If a customer buys one of our contamination kits and has an injector failure within the warranty period, we will repair or replace the injectors the first time at no charge to the customer
Bobcat Contamination Kits
