The rpm needed to light the fire will vary according to the application, but General Motors says its 6.2L and 6.5L diesels with Stanadyne rotary injection pumps need at least 100 rpm when cold, and 180 rpm when hot. The next thing that needs to be checked is minimum cranking speed. For really cold weather, you might recommend a CG-4 rated synthetic motor oil. Switching to a lighter oil such as a 10W-30 (never anything lighter in a conventional oil!) may be all that's needed to improve cold cranking.
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Ask the customer what kind of oil he's been using and when it was last changed. If the oil is thick and globby, it may not be the correct viscosity for winter driving. One of the first things you should check when diagnosing a "hard to start" complaint, therefore, is the dipstick. The increased drag created by the cold oil can reduce cranking speed to the point where the engine may not generate enough cranking compression and/or fuel pressure to light the fire. Straight 30- or 40-weight oils would definitely be too thick. The 15W-40 multi-viscosity motor oil, a popular warm weather choice with many diesel owners these days, may become too thick when temperatures go below freezing or plunge to zero or below. At the same time, battery output drops, reducing the number of amps available to crank the engine. First, the oil in the crankcase thickens. When temperatures drop, several things happen that can make a diesel hard to start.
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But diesels are also known for their idle clatter, black smoke and cold-weather starting difficulties. That's why diesels continue to be a popular option in many pickup trucks today. They're also known for their pulling power and rugged durability. Light-Duty Truck Diesel Engine Diagnosis & Repair by Larry Carley copyright 2019 ĭiesel engines are real misers when it comes to sipping fuel.
7.3 INJECTOR DRIVER MODULE FAILS WHEN WARM MANUALS
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