S195 No fuel injector pump output

[stevek]

Thanks Ronmar, I'll try and check the injector tomorrow.

The fuel rack moves freely up to the point that it hits the pin in the fuel limiter. This is right at the 'start' position on the speed control knob. What it's doing beyond that is hard to judge since it's the spring on the speed control lever against the spring in the fuel limiter pin.
One thing I haven't noticed while bleeding the fuel lines is any difference in pump output with the speed lever at 'start' and with it at 'max rpm'. Kind of points to what you mentioned about not delivering enough fuel to sustain combustion. I guess I could remove the fuel limiter to allow the rack to move full travel and see if I notice any difference in pump output.

I might be back where I started with no (or low) pump output.

Also, can someone tell me more about the "clink" I should be hearing when the injector fires?
From what I read it should be very noticeable, I don't think I'm hearing it.
Is it something I should be hearing from the injector itself?
If it is not present what do I do to fix it?

[mike90045]

I've found it takes me about two hours of rocking the flywheel back and forth, to purge all the air out of the pump, and then the fuel delivery line. Then I get the good "clink" or "creak" of the injector actually firing, and then she will start.

Can you turn it past the compression stroke without using the de-compressor cam ?  If so, you may have compression loss. Or you are really beefy !

[stevek]

Mike,
I'll take the easy one first, compression seems to be real good. Can't crank it through by hand without using the decompression lever.

Now, about rocking the flywheel back & forth to bleed the pump and lines. Do you mean that literally, as in find the spot where the cam actuates the pump and rock the flywheel back & forth?  It will be a long two hours but I'm willing to try anything.

[Ronmar]

The clink/creak is the sound the injector makes as the firing pressure is reached and the injector pops open and sprays fuel.  Too much air and the injector makes no noise as the air in the system absorbs the pressure generated by the IP.  As you get the air out, the injector will start to make noise as it opens/fires harder.  When cranked slowly by hand thru firing, the injector will make a series of rapid clicks as the pressure builds and is released in pulses.  As you increase the cranking speed, the clicks get closer together untill they blend into one single creaking noise...

[stevek]

Having never noticed any such sounds coming from the injector, looks like I haven't bled the air out of the fuel system yet.

Thanks for the help guys, I'll let you know how I make out.

SteveK

[stevek]

Good news & bad news: Got it to start but definitely not a normal start.

Here's the good news. Bled the fuel system again. Hooked a hand held vacuum pump to the fuel line at the injector and held a vacuum on the line while cranking over it by hand. Took about 5 minutes but started getting a consistent spurt of fuel with each revolution of the flywheel. Hooked up the line and bled again, then listened for the injector to snap which I finally heard. Had to listen for it, wasn't a loud as I was expecting but it was consistent with each revolution.

Now the bad news. Will only start with the speed control set at least 2/3 of the way between the 'start' setting and max rpm. When it lit off I got a little nervous as the rpm seem to be climbing too high too fast so I reduced the speed control toward 'start' and it shut down. Got a lot of whiteish smoke during the whole process and one very loud unusual bang from the engine, sounded like a backfire. (my knowledge of diesel engines is limited to the parts I can associate with turbine & gasoline engines so I may not be using the correct terminology)

Tried this two more times, same result each time. The last time it tried it I let it run a bit longer and got the same results but with several loud bangs. Shut it down after the second one.

Max run time on the last attempt was about 5-7 seconds from the time it lit off and was accelerating.

Several other observations:
1) It continues to occasionally blow out a very black fluid from the exhaust. I attributed it to the accumulation of fuel from multiple failed start attempts. While cleaning it off I noticed it doesn't have distinct fuel odor, has somewhat of an oil smell to it
2) I had the engine oil level topped off to the full mark yesterday. Checked the oil level after doing the sniff test on the gunk coming out of the exhaust and it was down 1/4" from the full mark. Using straight 30 wt oil, the manual specifies HC-11 (summer) or HC-8 (winter) and I've had zero luck figuring what what that means in english. Figured straight 30 wt was a safe alternative at least in the short term.

Could I somehow be getting lubricating oil into the combustion chamber or am I over-thinking the problem again?

I'm going to try draining the fuel again and putting in honest to goodness diesel fuel. I went with this type of engine under the impression it would run on about anything but I'm running out of ideas. And the "backfiring" has me nervous, don't want to do serious damage to the engine while I'm in my (apparently very steep) learning curve.

[possumlivingdotcom]

The backfiring makes me think the timing might be retarded. If it was mine I would probably remove one shim from under the pump body, then try it to see if that helps. If so, either find true TDC and set the timing to factory specs or just remove one shim at a time until it runs acceptably.

[stevek]

pldc, it's worth a shot. I have the injector out and have been looking for someone who can check it for me but not having much luck. Unfortunately my 'stuff' has expanded to fill all the available space in the garage and I can't get to the engine to work on it. Spring cleaning is right around the corner, I'll have a go at it when the weather turns. I've gotten pretty adept at getting the pump out & back in.