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High fuel consumption


Bulletin Today, April 2, 1982
by Roberto C. Bernardo

Under normal conditions, diesel engines are low on fuel consumption. This advantage is being magnified more by the prevailing cheaper cost of fuel. As commonly noted, it gives more kilometers per cheaper liter of diesel fuel.

However, this advantage could very well be upset by mal-conditioning in three areas namely; fuel system, engine proper (otherwise termed as “low compression pressure”), the drive line of the vehicle.

Among the three enumerated areas, malfunction in the fuel system is the most common point where the problem of high fuel consumption is often traced - particularly on the injection nozzles or bad spray formation or on the too low setting of its injection pressure. It could also be due to unequal or excessive injection quantities or improper injection timing.

Unequal or excessive injection quantities could be an indication of a damaged plunger and barrel, broken plunger spring, and malfunctioning in the delivery valves.

Improper injection timing could be worn down or loose tappet rollers or bolts, possibly worn out coupling.

Bad spray performance could be mean burnt needle of nozzles or broken nozzles spring clogging of carbon on the nozzle hole.

Too low setting of injection pressure may be a case of loose nozzle adjusting screw.