Machinery Used Farm Equipment Diesel tune-up tips A 9-point plan for peak diesel performance. By Ray Bohacz Ray Bohacz Ray Bohacz is a technical writer in both the automotive and agricultural industries and has been featured in more than 44 different magazine titles with over 3,000 published technical articles. Additionally, he has authored three books and delivered countless seminars to the two communities. Successful Farming's Editorial Guidelines Published on March 11, 2020 Close The modern diesel has come to depend upon tune-ups as much as gas engines have. Due to the myriad diesel applications found on the farm, apply the following procedures that are relevant to each engine. READ MORE: Shopping for used UTVs? Voltage sensitivity: Modern electronic diesel engines are very prone to misbehavior if the alternator output is weak, there is a high impedance in the ground circuit(s), if a battery has become sulphated, or if the battery terminals have become corroded. Mass airflow sensor (MAF): Located in the intake track after the turbocharger, most MAF systems use a hair-thin sensing wire. The MAF determines the airflow into the engine and the data is employed for every aspect of the way it runs. There can be no air leaks before or after the sensor. In addition, the sensing wire needs to be kept clean with a dedicated spray identified as a MAF cleaner. Simply remove the sensor and spray the electronics with the MAF cleaner. Do not use carburetor or throttle body cleaner! Throttle body: New diesels utilize an electronically controlled throttle plate, which tends to gum up. To eliminate this, remove the intake duct and spray the throttle plate with a throttle body cleaner with the engine off. Open the throttle plate by hand and using a rag, spray the cleaner and scrub both sides along with the throttle bore. Change EGR cooler coolant: Most engines with cooled exhaust gas recirculation (EGR) use a dedicated coolant supply that is not mingled with the engine coolant. Be sure to service the EGR coolant when tending to the engine's main radiator. Induction hoses: Clamps retaining the induction system hoses will loosen and have the potential of leaking fuel on the pressure side of the injector. Go around and snug all clamps. Clean fuel injectors: Even if you use premium diesel fuel, you should treat fuel with a strong dose of brand-name injector cleaner every 4,000 to 5,000 miles (or equivalent hours). The injector's ability to atomize fuel is paramount to engine performance, emissions reduction, fuel economy, idle quality, and cold-start ability. Also, if an engine has a HEUI system, be sure to add a stiction eliminator in the engine oil. READ MORE: Prices plument on trucks Treat the fuel tank: This a continuous tune-up treatment, as even premium fuel gets degraded during transportation. Treat all fuel with a product that raises cetane, stabilizes the fuel, minimizes deposits, cleans the injectors, and is an anti-gel. An engine's combustion events will be more efficient as a result. Not only will the engine run better but also the emissions system will have an easier life. This means fewer regeneration cycles, minimized use of DEF, and less carbon in the EGR and turbocharger. Variable vane turbo (VVT): The rings on the turbine (exhaust) side that control the turbocharger's effective size can carbon up and stick. If the engine runs efficiently and idle time is limited, then every 100,000 miles, remove the turbine housing and clean off the carbon from the vanes and ring. Replace oxygen sensor: Most light-duty Tier 4 engines employ an oxygen sensor. Once the sensor reaches around 150,000 miles, replace it with a new unit to keep the fuel delivery and EGR functions accurate. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit