Join Date: Oct 2008
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3GM yanmar hard starting
I am helping a friend with his 92 era 3gm in a 1992 35.5 hunter. I have had a similar engine in a 1991 37.5. My 37.5 3gm always started very quickly, hardly turning over on starter before firing up on all 3cylinders. My buddies engine started the same untill about two years ago when at times when stated after sitting for a day or two, it required a lot of cranking and eventually started running, roughly for 30seconds or so with a fair amount of black smoke. We have been trying different things to solve this startin problem the things that have been done are:
mixing elbow change, clean fuel filters , new injectors, injector pump rebuild, new hight pressure steel lines from injector pump to injectors, compression check ( within limits) we now notice fuel weep from the area of the injectors where the high pressure steel lins is attached, found by using paper towel blotting after running engine for 15 mins or so. we are fairly sure that this may be the cause of this agravating problem We are wondering how tight should this compression coupling be torgued down? And has anyone had this type of problem and actually solved it?
The engine still behaves the same hard stating after sitting for a day , but runs fine when warmed up. Starts fine unless it sites for a day. I did find a post from a fellow who had the same experience in 2008 but solution to the problem was never posted on this forum.