Yanmar injection pump question

[JoeJChin]

Well been playing with the tractor all day today , (closing in on 8:00pm now) and no luck .

First thing i did was drain out all the old fuel,, flush out the tank , so i could start clean(don't know what might have been in there when i bought the tractor)
I put a compleley new fuel filter assemble on it , the old one looked like it might have been leaking at the shutoff valve and fittings, I also changed all the fuel hoses .
I wanted to eliminate any place it might be leaking or sucking in air when trying to bleed it .

While trying to bleed it , by cranking the engine over , i finally got a little bit of fuel comming out of the line at the #2 and #3 injectors, nothing at the # 1 injector.

How much fuel should i be seeing at the injectors , while cranking the engine?

What i am seeing at no 2 &3 looks like just a few drops at a time , and i have lines quite loose

The amount of fuel comming out kind of looks like it would if you had an "eyedropper " and were squeezing a drop or two at a time out of it .

I really don't want to buy an injection pump if i don't need it , but i'm not sure were to go at this point......

If i should be seeing more that just a few drops while cranking , then maybe the pump is bad .

any help appreciated
I have one more day of "OK" weather , then we drop down into teens for a HIGH temperature for the next week.......................

thanks

Joe

 

[winston1]

If you started with the closest bleed to the tank and worked your way to the injectors and are only getting an eye dropper on two of them and nothing on the other one it is possible your pump rack is not wide open or your plungers are sticking. Try tapping on the pump a little, probably won't help but won't hurt either. Again, my answer is based on you having a good/bled fuel supply.

 

[dirtdonkey]

I was amazed when I saw all the more that comes out when the pump is working. Its a very small amount at an extremely high pressure, 2100 PSI, according to the manual. The new pump I installed put our far more than my old pump but my tractor seemed to be running fine with the old pump when it quit one day. Remember all it does is come out as a fine mist from the injector into the cylinder when it works so you're not looking for a large volume. I'm assuming you're checking it with the throttle held wide open while you're cranking the tractor over? I was where you are when I ordered my new pump, because I thought my pump was the problem and everyone I spoke with seemed to think the same thing. Its a lot of money for the pump though so I'd check to make sure there is nothing else wrong before I ordered a new pump. Like Winston said you have to make sure that you bled the pump good or you won't get anywhere because it can't pump air.

 

[JoeJChin]

Well .

Time to post an update on this problem ...........

Ended up buying a new injection pump. It was the only thing left to try that made any sense.

Turns out that was the problem , while bleeding out the new pump , I (like dirtdonkey ) noticed a noticeable increase in the amount of fuel coming out at the injectors .

Tractor seems to start easier now also .

Now all i have to do it check to see if the timing is ok on it.

I installed the new pump with the old shims on it , i didn't run the tractor much at all, just to see if it would start and run .

Have to check out the timeing procedure for it .

Thanks to everyone for their help

Joe