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Volvo KAD43 Hard to start after 3 days.

gmikell

New member
Investigation reveals that Volvo diesel fuel filter is about half empty after motor is idle for 3 days or more. It appears that fuel is leaking back into fuel tank. Motor will start after fuel is regenerated (about 10 seconds of cranking). Once started eng exaust is very smokey. What allows fuel to draing backwards into fuel tank ? Is there a possibillity that fuel is leaking through the return line ?? Maybe fuel injectors leaking ? -- What procedures should I use to isolate the problem ?
Eng has about 2500 hrs -- Fuel injector overhauled about 300 hrs back -- Injectors reconditioned about 700 hrs back -- new fuel pump 50 hrs back --
all fittings have been re-tightened -- compression is good.
Does anyone have a suggestion of how to resolve this problem.
 
May not be a fuel problem at all.Check your pre-heaters.If the smoke you mentioned smells of unburned fuel (not unusual for a cold engine) then perhaps the delay in starting is a result of a very cold engine (no help from pre-heaters)
 
Thanks for the reply. I have replaced the fuel primer pump to no avail. I think this problem is being created by an air leak somewhere forward of the filter, maybe a missing metal gasket ? We have a dozen Volvo kad43's in the Brookings vicinity and 4 of them have this problem. I amin the process of checking all fittings and hose connections.
 
Just as a thought, have you got valves in the feed and return lines at the tank? If so, a test would be to turn off both valves after a run and then check for fuel levels in the filter etc after a few days sitting idle. If the filter is still full, do the same again with only 1 valve closed etc until you can see what is happening better. At the same time, check the absolute level of the fuel vs the height of the injector pump, filter, injectors etc tto see what should, and shouldn't be able to siphon. Won't fully id the problem, but may supply some good clues.
 
aliboy
Thanks for the input -- I just just recieved local feedback which indictes the air/leak might be coming from the fuel tank pickup line. This makes since because there is foam in my filter when I purge the fuel pump. Air has to be coming somewhere between the motor line input and the fuel tank. I have eliminated the RACOR by removing it from the system. The fuel pump has been replaced. Today I will remove the pickup and inspect.
P.S. The symptom of initial hard start after sitting for a few days, seems to be wide spread. I will keep all advised on what is found.
jerry/fishbuster7
 
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