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| One of the most common diesel complaints is a hard to start or will not start situation. Every detail is important when trying to diagnose such a problem. One should determine if engine temperature has anything to do with the problem, ambient temperature should also be considered. Close attention should be paid to the cranking R.P.M. as well as the glow plug system. Starting problems are often electrical related since cranking R.P.M. and the glow plug system are very critical to getting the fuel to burn. Batteries and the starter should also be a consideration if cranking R.P.M. seems slow. Once the electrical system is ruled out, air entering the system should be considered, especially if the engine cranks, dies and is then hard to restart. Air can enter the system through any break in the fuel line or through a bleedback condition. To determine if air is the problem, install a clear return hose on the return side of the injection pump. If air comes out it is getting in the inlet system someplace. The injection pump is very seldom the cause for air entering the system. In most cases the fuel lift pump or a faulty inlet line usually ends up being the problem. Engine problems can also be the cause of starting problems. Low compression or timing problems can start out a hard to start condition. Checking these usually involves special tools but it can save a lot of troubleshooting time in the long run. Fuel supply and quality should also be considered when searching out a hard to start problem. If the vehicle never starts a fuel restriction may exist. Fuel quality is an important part of getting a diesel engine started. Poor quality fuel may not burn properly leading to poor starting. If this appears to be the problem, adding a conditioner such as Stanadyne's Performance Formula may be just the cure. In extreme cases the fuel may need to be changed out and the system reprimed. The pump and injectors can occassionaly cause a hard starting condition. If a fuel mileage drop or increase in smoke has been experienced the injectors should be suspect, especially if they have ran 75,000 miles or more. If there is no fuel coming out of the injection pump then it becomes a major suspect. First determine if the solenoid is opening by listening for a "click" inside the pump when the ignition switch is turned on. If no click is heard then the pump needs servicing. If a "click" is heard but still no fuel is being pumped, fuel supply and air in the system need to be ruled out as potential problems. One might try using a fuel lubricant such as Stanadyne's Performance JUNIOR, in case the metering valve has stuck in the shutoff. This will sometimes help weak injectors also. If all of these checks are to no avail the injection pump should be removed and serviced by an AUTHORIZED repair agency. Randy Norton
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