803A droop adjust screw?

[Waterhouse]

Take the hard line on the problem cylinder, off the metering pump and see if its pumping fuel while running. If it is, as Ray points out, look to the injector next. That can also be tested installed, but removed from the head with the hard still attached.

You will want to figure out what isnt wrong with that jug first before throwing money at it.

If you read my post #56, that was the first thing I did and it was spraying fuel all over. What I don’t get, is you seem to be suggesting the injector is not fueling the cylinder. It is over fueling it, so I don’t get the purpose of your test.

 

[Guyfang]

Look at your oil. Is it thin? Smell like fuel? If a jug is getting too much fuel, its going to leak some into the oil.

 

[Ray70]

The purpose of the test is to see if the injector is over fueling the cylinder.
The metering pump does not deliver just the amount of fuel required for each power stroke.
The injector opens at about 3000 PSI, sprays 1 fine mist of fuel then closes once the pressure drops below 3000 PSI. , the remainder of the fuel goes up through the body of the injector and back through the return line.
If the injector is stuck open or leaking it will definitely deliver way too much fuel than that cylinder is supposed to get, and it won't be atomized, it will be more of a drip AND the fuel will not be delivered at the correct moment.
The metering pumps and injector volume and timing are all set with the assumption that the injector needs 3000 Psi to open and close. Anything else will result in incorrect fuel delivery.

 

[Waterhouse]

The purpose of the test is to see if the injector is over fueling the cylinder.
The metering pump does not deliver just the amount of fuel required for each power stroke.
The injector opens at about 3000 PSI, sprays 1 fine mist of fuel then closes once the pressure drops below 3000 PSI. , the remainder of the fuel goes up through the body of the injector and back through the return line.
If the injector is stuck open or leaking it will definitely deliver way too much fuel than that cylinder is supposed to get, and it won't be atomized, it will be more of a drip AND the fuel will not be delivered at the correct moment.
The metering pumps and injector volume and timing are all set with the assumption that the injector needs 3000 Psi to open and close. Anything else will result in incorrect fuel delivery.

Ok, that sounds possible. I hope you’re right. I’m sure an injector is less money than a pump.

Let me ask you this. Does the pin in the governor rack shut the fuel off completely? It would appear so since that seems to be the way it shuts down. That Might explain why it took so long to shut down in if that one injector took awhile to go dry.

Anyways, thanks for the info. I guess I got to figure out how to pull an injector. Can that be done without removing the entire case?

 

[Ray70]

Yes, the pin in the metering pump shuts off the fuel completely when the rack rotates it fully, that is how the machine shuts down.
You will need to pull the cover off to remove the injector.
If you have trouble getting the injector out, the thread on the top is metric, same as some lug nuts. I think it's 12mm if I recall.
In the past I've threaded lug nuts on upside down and used a slide hammer with a flat hook to pull up on the lug nut to remove stubborn injectors.

 

[2Pbfeet]

I have seen poor injection caused by residual air in a fuel line; as @Ray70 points out the fuel regulation and injection is dependent upon the fuel in the line to the injector being incompressible to deliver fuel to the injector. If the air is trapped there, the pressure pulses, but never gets to a high enough pressure to inject. Some engines (injection pumps) are better than others at flushing air out.

After re-reading @Waterhouse's posts, it is not clear to me that the injectors have ever been tested to see if they function. That would be my next step.

All the best,

2Pbfeet

 

[Ray70]

Seeing that he mentions needing to figure out how to get the injectors out I'd say he has not tested them.
I think he removed the lines and just verified fuel flow through the lines.

 

[Waterhouse]

I have seen poor injection caused by residual air in a fuel line; as @Ray70 points out the fuel regulation and injection is dependent upon the fuel in the line to the injector being incompressible to deliver fuel to the injector. If the air is trapped there, the pressure pulses, but never gets to a high enough pressure to inject. Some engines (injection pumps) are better than others at flushing air out.

After re-reading @Waterhouse's posts, it is not clear to me that the injectors have ever been tested to see if they function. That would be my next step.

All the best,

2Pbfeet

No, I have never had the injectors or pumps tested. (Other than cracking the hard line and spraying fuel.)

 

[Ray70]

Pull the top cover and get the injector(s) out. Reattach the hard line by moving the line off to the side. You should have 4 finely atomized mists of fuel spraying radially out from the tip of each injector as you crank it over. You will probably need to bleed out any air in the lines if you disconnect both ends. ( note, you can't use the dead crank switch to crank it unless you disconnect or manually retract the fuel solenoid.)
Any dripping, squirting or stream of fuel coming out means you have a problem.

 

[Waterhouse]

I got four used injectors coming. I’m going to do the test when I have them in hand.

Thanks

 

[Waterhouse]

Ok guys, I got the four injectors and the hold down clamps. I took a look at the TM and it has an exploded diagram of exactly what I got. Something is confusing. There doesn’t appear to be anything that the hold down clamp goes against. There is a groove around the injector that I figure a cir clip might go into, but they don’t show it in the TM. (they show the groove, but no clip) What am I missing?

I plan on attempting to change out (and test) the injector without pulling the cabinet. It appears there’s enough room. I would like to pull the cover, but I don’t see how you get to some of the interior nuts up by the radiator. Is it possible that those nuts are secured on the inside so I don’t have to hold them? I don’t really want to start undoing them and get loose nuts that I can’t remove or tighten up.

 

[Light in the Dark]

Do you see the cast iron hold downs that keep the metering pumps in place on the side of the engine? Very similar concept to what's up top for the injectors.

You will want to take the roof off over the engine for this. The screws over the radiator and elsewhere screw into captive nuts, just undo them and the nut stays in place.

 

[Waterhouse]

Do you see the cast iron hold downs that keep the metering pumps in place on the side of the engine? Very similar concept to what's up top for the injectors.

You will want to take the roof off over the engine for this. The screws over the radiator and elsewhere screw into captive nuts, just undo them and the nut stays in place.

I got impatient and pulled the injector without removing the cover. (PITA) The injector looked like this. Mine is the one on the right. The other is one of the used ones I bought.



I installed the old injector in the line to the side of the motor. Kind of a pain because I didn’t want to bend the line at all.



I ran the motor and the jug filled up with a haze. Then I put one of the replacement injectors on and ran the motor. It also filled the jug with haze, but it was much quicker. Don’t know if that’s a good thing or not. I’m just going to try one of them and see.

New question while I wait for it to cool. The new (old) injectors came with hold downs and bolts. The bolts have a cone bottom and the hold down has a cone hole for the bolt to fit. My old hold downs have a flat surface with Allen head bolts. Should I switch to the new (to me) hold down/bolts?

 

[Waterhouse]

Well I put it together with the new injector and it smokes like a steam shovel. So I guess I’m going to tear the pump apart.

 

[Waterhouse]

Pump apart. I found this pic on this site.



Here’s a pic of mine.



You see the inner sleeve I removed from mine. I’m sure the other guy just didn’t know it came out.

Nothing looks real obvious wrong. I do wonder what the extra o-ring in his pic is.

At this point im thinkin* of more shims under this. I assume it will pump less fuel the more shims I have.

 

[Ray70]

The shims don't adjust the amount of fuel being delivered, they adjust the pump timing.
Rotating the pumps within the block adjusts the amount of fuel being supplied by altering the position of that slash cut notch in the plunger.