Oil & Fuel Fuel Pump Timing Help??

[Gizmo36]

I just had the same thing going on .Work on it for a mouth, It was hard to start .Then black smoke was so bad . I had a hole in the fuel line It was getting a little air in it..I put a new fuel line on an got all the air out and that fix mine.

 

[FleetMan]

Mark,
Have you checked the compression. Your last post indicates the engine may have been subjected to too much ether for easier starting at some time in the past. The ether washes the oil from the cylinder walls causing premature ring wear. This results in reduced compression and long, hard starts. The lowered compression extends the amount of time it takes for the temperature in the cylinder to reach the point for auto ignition. Raw fuel out the exhaust before starting helps substantiate that point.

 

[normde2001]

How would the average shadetree mechanic actually accomplish a compression check on a Yanmar /forums/images/graemlins/confused.gif?

 

[FL_Jerry]

If the pump seal blew because of a problem in the hydralic system, could a severe load caused by fixing the seal cause it to run like that? Only reason I mention a far fetched idea like that is my Koyker installation manual mentions after hooking up the hydraulic lines and starting the engine to shut it off if it runs poorly. I also talked to the owner of the company that services our diesel generators(100kw) about your problem. He tells me that black exhaust shows an engine under heavy load. Anyway, might be something else to check.

Good luck!

 

[greatrandini]

I would replace the fuel bowl, fuel filter, and o ring. Then completly rebleed the fuel system up to the injector pump. The reason I say this is because I once had my unit act similar and that is what I did because I saw an ocassional drip from the fuel bowl area. I think you are sucking air into the fuel system from somewhere!! Check the simple first.

 

[mark777]

Thanks for all the great suggestions and advice..even ones that seemed a little far fetched I tried. It looks as though I'll be tearing it down tomorrow (or Sunday) as every attempt has not altered the way the tractor runs or operates.

It would seem the mystery lies further down, as in or under the head - maybe cracked valve seat..even though it miss-fires randomly, it just can't be anything from the outside as I have double and triple checked it all. I'll let everyone know what I find and again thanks for the help!

Mark

 

[greatrandini]

I saw where Harbour Freight has a disel engine compression tester on sale. I can't remember how much but it was something like $20 or $30. I was suprised to see a kit that cheap. It is suppose to have adapters for various engine and comes wiht instructions. If you are interested google Harbour Freight.

 

[greatrandini]

Check this out at Harbor Freight tools.

Designed to check compression on most domestic and foreign diesel engines.
Quick-connect adapter
Reads pressure from 0 to 1000 PSI
2-9/16" diameter gauge
Thumb button air release
Comes with adapters for GM, Ford, Lincoln, Isuzu, Mercedes Benz, Kubota, Toyota, Volkswagen, Peugeot


ITEM 93644-2VGA
$24.99

$19.99 Email link to a friend

 

[normde2001]

"Comes with adapters for GM, Ford, Lincoln, Isuzu, Mercedes Benz, Kubota, Toyota, Volkswagen, Peugeot"

What do you suppose the chances are of any of those adapters fitting a Yanmar?

 

[HGM]

Mark, Before pulling the head off... What about fuel quality? I would expect it to be white smoke, but I'd check it since it seems you've checked everything else.... If not the fuel, maybe the injectors are leaking for some reason....Low compression should be white smoke too.... Logic tells me its still too much fuel or not enough air, but good luck and please let us know... May run into it myself one day... /forums/images/graemlins/blush.gif