"Help! I have a Yanmar 4JH3-TE
"Help! I have a Yanmar 4JH3-TE; 1997 but only 70 hours. Ran perfectly until a big trip in July; after 6 hours hard running it died when returned to idle; starting up would only get to 1800RPM,then after 5-10 minutes suddenly would get full power and happily go all day, only to die again whenever idled. Mechanic recommended diesel fuel conditioner at high concentration; tried without success; eventually pulled injector pump and had it rebuilt (all except hydraulic head); problems persisted on re-installation. Found a similar engine with a cracked block; installed its injector pump; worked fine on first trial, then identical problem. Swapped out inejctors; no improvement. Mechanic suggested fuel might be bad; today spent 4 hours discarding fuel, cleaning tanks (indeed dirty with gel-like layer on bottom), replaced dual Racor 10-micron primaries and yanmar secondary filters, flushed with brand-new diesel from busy gas station, primed lines to injectors.... ran motor directly from jerry-jug of fresh diesel; same problem. Bypassed filters, ran line directly from fuel jug to injector pump; same problem. I am stumped!!!! Any suggestions?"
"Help! I have a Yanmar 4JH3-TE; 1997 but only 70 hours. Ran perfectly until a big trip in July; after 6 hours hard running it died when returned to idle; starting up would only get to 1800RPM,then after 5-10 minutes suddenly would get full power and happily go all day, only to die again whenever idled. Mechanic recommended diesel fuel conditioner at high concentration; tried without success; eventually pulled injector pump and had it rebuilt (all except hydraulic head); problems persisted on re-installation. Found a similar engine with a cracked block; installed its injector pump; worked fine on first trial, then identical problem. Swapped out inejctors; no improvement. Mechanic suggested fuel might be bad; today spent 4 hours discarding fuel, cleaning tanks (indeed dirty with gel-like layer on bottom), replaced dual Racor 10-micron primaries and yanmar secondary filters, flushed with brand-new diesel from busy gas station, primed lines to injectors.... ran motor directly from jerry-jug of fresh diesel; same problem. Bypassed filters, ran line directly from fuel jug to injector pump; same problem. I am stumped!!!! Any suggestions?"