S195 No fuel injector pump output

[stevek]

Started my S195 for the first time a week or so ago, ran for about 10 minutes but never was able to get above idle, it shut down when I tried to increase the speed. Since then I haven't been able to get it to start.
  Found there was very weak, sporadic output from the fuel pump. Would only spit out a miniscule bit of fuel about every fourth revolution of the engine. Could never get the fuel line at the injector to bleed properly, cranked with the starter till I figured I'd probably burn it up if I didn't stop, then hand cranked myself to just short of a heart attack. Never got anything resembling decent flow at the injector fitting.
  Took the pump out, disassembled and reassembled using some references I found on-line. Everything appears to be fine in there:
No corrosion, everything moves smoothly, seems to be the proper fit between plunger & barrel, reassembled with the rack centered, timing marks lined up and plunger inserted with the helical groove facing the rack, metering valve in the output barrel (correct terminology?) all assembled correctly, and most importantly there is good fuel flow to the pump. Now I have no output at all.
  No difference whether cranking by hand or with the starter. Even tried applying a slight vacuum at the pump outlet to try and pull some fuel through the pump while cranking by hand. No luck.

Am I missing something basic? It's not that complicated of a mechanism, I'm 99.9% sure I have the pump assembled correctly but I'm out of ideas.
Any help available from those more experienced and wiser than I?

Steve K

[veggie]

Perhaps I am stating the obvious but...
Have you checked the flow to the fuel pump.
Clogged filter ?
When you open the fuel tap does it flow freely through the pipe to the fuel pump connection ?

veggie

[stevek]

Thanks for replying veggie. Yes, there's good flow to the pump, gushes out when the banjo fitting at the pump is loosened.

[Thob]

Is there enough lift from the cam to the pump?  How do you adjust timing on one of these?  If it's like the lister pump, it's possible that the timing adjustment has backed off so much that the cam no longer lifts the pump enough for the fuel to flow. 

[playdiesel]

Turn the engine until it comes up against compression and back it up a 1/4 turn (You do not want the pump cam lifting the plunger) then  remove the delivery valve cap and spring and pull the delivery valve off the seat with your finger, fuel should run out the pump if not you have a fuel flow problem.  Also are you sure you got the rack lined up in the slot on the governor arm?

[Henry W]

Is this an engine that had never been fired up until a week ago?

[Ronmar]

I am new to the changfa design, but if I recall correctly my 1115 has a little hex head nut right adjacent to where the IP is located on the side cover.  This nut when turned strokes the IP, to allow you to prime the injector HP line and purge air without rolling the engine over.  I think if this nut was in the wrong position, it will hold the pump plunger in the stroked position and prevent it from filling and pumping fuel?

[Henry W]

A word of caution:

When working with high pressure fluid, keep your hands, eyes, face protected from spray. It is very dangerous and people lost limbs and died from being injected with fluid.

[Henry W]

Yes Ronmar,  that will hold the injector pump from working.

[vdubnut62]

Where the heck is Bob? He's the resident 195 Guru.
No disrespect meant to present company!
Ron.

[mobile_bob]

a bit late to the party i see,

i had an issue with a 195 fuel pump only once,
it was related to air in the high pressure line.

you certainly want to loosen the bango fitting bolt on the suction side, and let all the air
out by allowing several ounces of fuel run out into a cup or some other receptical

and then leaving the high pressure line loose, move the throttle lever to full fuel position
and crank it up until all the air is expelled in the line up to the injector... once there is fuel squirtin
out all over the place while cranking just tighten the fitting to the injector and it should start right up.

failing that, there is an issue in the pump, that is if you don't get a decent quantity of fuel squirting out at the injector line to injector connection (line nut).

let me check the parts and service info i have and see if i can see what might be the underlying problem.

brb
bob  g

[rcavictim]

Correct me if I'm wrong but isn't that lockable bolt/nut on the side cover to act as the fuel limiting adjustment so you cannot put too many coals to her at max throttle?

[mobile_bob]

just found my info

sounds like the pump never worked properly because the engine would not run over idle

i would recheck the following

the fuel delivery valve, make sure it is in correctly the right direction
the fuel delivery valve seat make sure it is flawless, no burrs inside where the valve seats
it has to seal here in order to pull a vacuum to suck in a charge of fuel into the pump.

check the fuel delivery valve seat, where is base meets with the plunger bushing, and the end
of the plunger bushing for burrs, or other damage that might keep the two from fitting together
perfectly, again it needs to seal well to pull a vacuum and draw fuel into the pump.

i am thinking there is likely a tiny burr somewhere, that is allowing fuel to bypass, or an air bubble
recirculate to and fro between the plunger and the injection delivery valve holder/fitting.

it doesn't take much air, and an air bubble sometimes can get caught in the weirdest places.

i suppose it is also possible the the injector is not seating properly either, allowing air to be drawn in
or forced into the fuel system from compression, so you might want to test that too.

check the injector line for obstruction, its unlikely but possible it has a piece of crap blocking it too
although the pressures involved ought to rupture the line.

bob g

[stevek]

All, thanks for all the input. Definitely gave me some things to look at  when I get a chance to spend some time on it, probably over the weekend. Short of time right now, will try and respond to some of the replies later in the week.

Steve K

[rcavictim]

Correct me if I'm wrong but isn't that lockable bolt/nut on the side cover to act as the fuel limiting adjustment so you cannot put too many coals to her at max throttle?

Or don't.