Help please. I changed the filter on my L1801. Let the bowl fill, tightened it up. Started and ran for about 5 seconds. Tried to restart and it would restart and run for few seconds. I found a quarter turn knob that looks under injector pump and let diesel run through. Tried again, no go. Opened the compression deal and cracked both injectors. Turned it over and no diesel coming out of injectors. This is a L 1801. Hasn't been serviced in a while. Help please. I can't afford a bill from a shop. Thanks.