98 Dodge ram 3/4 ton diesel. when the key is in the ignition -not on- the fuel pump runs and tbe wait to start light comes on, will not start. Tried jump starting.
something not right, nothing till turned to on should be,then wait light ,try the on position that fires the glows not in off position. and the light for glowplugs is just a indicater it dont know if glows are shot or not, test light them
Is this a 98 12 valve truck, or a 98.5 24 Valve truck? You're saying when you insert the key into the ignition without turning it at all the fuel pump is running and the wait to start light is on?
It sounds like you are putting the key in, and turning it to the 'RUN' position, where the glow plugs would normally be turned on. You hear the pump running continuously, but it won't start. If I am right, this sounds like one of the pumps is not working. I believe you have 2 separate pumps. One in the tank, and then a second, lifter pump, external. If the tank pump is not working the lifter pump does not have a proper supply of fuel. If it is the lifter pump, the tank pump cannot produce enough pressure to start the truck. You could also have a bum regulator. I believe on that system that there is a pressure switch that illuminates the wait light if there is insufficient pressure to start the truck.
There is no fuel pump in the tank. That didn't start until 2005. There is a lift pump mounted on the side of the engine block and an injection pump mounted on the front gear cover and driven by the camshaft. The wait to start light has nothing to do with fuel pressure. It is controlled by the PCM and determines how long to run the grid heater based off of coolant temperature. The colder it is, the longer it cycles the grid heater. The first thing I would check is if you are actually getting fuel. Just because the lift pump comes on doesn't mean it's working sufficiently. The easiest way to do this is pull the lid off of your fuel filter housing and make sure it is full. If it's not then cycle your key on and see if fuel sprays into the housing. If it's full then I would try to bleed the system out and see if it will start. Loosen the injector lines at the head and crank it. See if fuel comes out and if it tries to start. If you have fuel coming out and it tries to start then tighten up the fuel lines. It should take off and run rough until all the air is out of the system and then clear up. If it's getting fuel through the fuel filter housing but not through the lines then you'll probably be looking at an injection pump problem. If it does start after bleeding the lines then you either have an internal injection pump issue not holding pressure or a faulty lift pump losing prime. More info would be helpful, but good luck with it.
7jimmy7: The Cummins dont have glow plugs. They have a grid heater
same function same principle,
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