case 480B Construction king---No Run....

gdiffee

New User
Hello Forum.

trying to diagnosis a problem with a 1975 case 480 Construction king backhoe/loader. has a G188D engine using a Roosa Master injector pump. Used it about a month ago and was running fine. went back to use it just a few weeks after parking it and it will only start on starting fluid. has fuel to the pump, and manual shutoff is working correctly. Pulled the timing plate on the side off to check to see if the shaft was working. When I pulled the plate, about a cup of diesel came out the port. Couldn't find my mirror to inspect to see if the shaft is turning but with the diesel coming out of the timing plate: is there a problem with the pump or is this normal... ?
 
The pump uses the fuel to lubricate it and it will be full,so it is normal for fuel to spill out when the timing window is removed,if the engine is starting with starting fluid and running the shaft can't be broken,you are the second person on here within a week that parked the machine and it would not start on returning,the most likely thing to happen to cause that is the metering valve to stick in the stop position esp if the stop is left pulled out,the metering valve is a spiral valve that turns in its bore,it is mechanically pushed to the stop position,but there is no direct link to return it to run except through a spring,should the valve stick the spring can absorb the motion and the valve not move,look through the other posts and you will find a picture of the valve,take the top cover off and have a look,make sure the return elbow is not blocked.
AJ
 
As AJ said most likely the metering valve is stuck in the off position, but look again and make sure the pump timing plate is turning when cranking engine. Would be a bummer to get the valve freed up only to find the head seized. If it still won't get fuel to injectors then I'd suspect stuck plungers and delivery valve also, have been seeing more like that lately..
 

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