In General.
Starter not Cranking Battery and Ground wires good:
The Neutral Safety Switch no good or. (“First make sure the selector is in P or N. Cycle through all the gear positions and try in N.
In front of the battery is a small rectangular box. Use a jumper wire to jump from one of the large posts to the small post with the purple wire. If it cranks, you've got an issue with the neutral safety switch or the ignition switch.

Above the accelerator pedal is a 4-wire plug with a harness that runs down to under the accelerator pedal and to the transmission tunnel. Unplug it, jumper across the two purple wires in the female plug and try to start again. If it starts, you need a NSS.”)

Ignition Switch not working. (In front of the Battery on the Fender Well is a Terminal Block. Clip a Remote Starter Switch to the left and right sides of the Terminal Bloc, or use a Jumber wire being careful not to get burned. If you are careful you can use this to start your Engine. If the Starter Solenoid does not engage and the Starter does not crank you have an issue with the Starter.)

Not starting due to no Fuel:
If the car has sat for a long time start pumping on the Hand Primer Pump untill you hear a squishing or squeeking sound. After that pump some more to be sure. That brings Fuel Up to the Fuel Injection Pump.
Air in the system. (Loosen the Fuel Injection Line Nuts at the Injectors and crank untill you see Fuel comming out. Thighten the Nuts and attempt to start.)

After you have pumped on the hand primer and loosened the Fue Injection Line Nuts at the Injectors and Fuel is not coming from the Fuel Injection Lines. (Change both Fuel Filters. Fill the Spin-on Fuel filter with Diesel Fuel but still pump on the hand primer. Leave the Fuel Injection hard Line Nuts at the Injectors loose until you see Fuel come out. ) (You could als could remove and install a longer Fuel Inlet Hose 5/16" ID using reglar Fuel Hose and run it to a Container with clean Diesel Fuel; you are doing this to see if something is keeping Fuel from coming from the Fuel Tank.)

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84 300D, 82 Volvo 244Gl Diesel