"kracked1" wrote:

If you havent felt the detent then you for sure dont have the fuel on. Keep checking, you have the problem solved. Just need to find out where it is stuck.

Now I'm rethinking this because the rack moves. After watching the governor rebuild video, it doesn't look like it's a detent.

Rack will still move some with it shutoff.

"kracked1" wrote:

Rack will still move some with it shutoff.

It moves all the way forward and back.

Edit: Watching Squatch install the pumps on 5J1113, after everything was installed, he moved the rack forward and backwards and it appeared to be spring loaded back through the governor spring. I don't recall it springing back, but I'm not sure this is relevant to not starting. I think it's worth popping off the pump cover again and pulling the governor cover.

I agree, keep looking, your getting closer.

It's spring forward and governor centrifugal weight back.

"Old wrote:

It's spring forward and governor centrifugal weight back.

I thought it was Spring forward, Fall back?

I'm hoping my memory is just bad because I don't recall any springing, either way. But, I need to check that again to be sure.

Without the engine spinning the governor you don’t feel the spring pulling forward and the governor flyweights opposing them. Once it’s spinning you should find the rack much less movable though you will still be able to influence the rpm by moving the rack. Governor should quickly return rpm to where it was without much hunting. That being said, most old governors have enough wear that AT LOW IDLE when governor forces are very light, they’ll tend to hunt.

I don’t think the D3400 governors have an over center shutoff detent like the D311s have. Instead there’s a spring loaded stop that you compress when you move the throttle lever to fuel shutoff. I’m guessing the notches in the throttle quadrant allow you to set the control to hold the internal governor lever against the stop with it fully compressed. Of course it all depends on wear and lost motion in all the throttle linkage joints.

How much smoke are you getting with the fuel on? Most of the ones I’ve dealt with will puff a little white vapor even with throttle closed. Once you open throttle, you should get a cloud of thick white smoke with puffs of black as the first cylinders start hitting. The white smoke should not be affected by low compression so if you’re not getting that, keep investigating a fuel problem.

If you can do a leak down test when/if the injectors are out, it’s roughly done by turning the engine to TDC of compression stroke, engaging clutch, trans in high gear, brakes locked so it cannot turn from the applied pressure. and then turning on shop air pressure of 100-175 psi. As mentioned earlier you’ll get an appreciation for where air is going by listening to intake, exhaust and crankcase vent. Air will be going by the rings no matter what shape the engine is in unless you’ve filled the cylinder with oil to block it, but the valves should be tight so that’s easy to check. The amount crankcase blow by that’s permissible using a home built test rig is a guess at best. Caterpillar specified a calibrated test rig to do the test and time leak down to get an acceptable/unacceptable result.

Hi Team,
there is not a detent on these it is simply an adjustable spring loaded Stop Plunger- Big Screw, that is adjusted to set the Low Idle speed.

Here is what I believe happens--I stand to be corrected--When the Operators Gov. Control lever is moved Forward to the Stop position the rack moves Forwards also and the internal lever pushes the plunger in against its spring to take the rack Forwards to a No Fuel position. In this position the rack should be solidly held Forwards by the linkage system.

In the Fuel On position the rack would be Rearwards and held there by the now stretched Gov. Spring awaiting the governor weights to push it back to a lower fuel (speed) condition.

See scans below.


WELL NOW seems I have again lost my ability to post more pics.

SORRY boys the last upgrade must have defaulted the system I guess.

Cheers,
Eddie B.

"edb" wrote:

Hi Team,
there is not a detent on these it is simply an adjustable spring loaded Stop Plunger- Big Screw, that is adjusted to set the Low Idle speed.

Here is what I believe happens--I stand to be corrected--When the Operators Gov. Control lever is moved Forward to the Stop position the rack moves Forwards also and the internal lever pushes the plunger in against its spring to take the rack Forwards to a No Fuel position. In this position the rack should be solidly held Forwards by the linkage system.

In the Fuel On position the rack would be Rearwards and held there by the now stretched Gov. Spring awaiting the governor weights to push it back to a lower fuel (speed) condition.

See scans below.


WELL NOW seems I have again lost my ability to post more pics.

SORRY boys the last upgrade must have defaulted the system I guess.

Cheers,
Eddie B.

Thanks Eddie. It looks like I was heading down the wrong rabbit hole. Fuel shut off is entirely controlled by the position of the helix or scroll on the plungers in the pumps. I got to thinking there was something else shutting off the fuel. Since the rack moves, the starting problem isn't in the gov. or ant linkage. How it runs when we get it running will be another story.

I really think I need to pull the injectors and hook them back up and make sure they are actually atomizing the fuel.

So I have been thinking that if the pumps were weak from wear or being scored or whatever, they would be bypassing fuel and it would be running down into the trays on the lifters. Is this true? Could they have a problem and I wouldn't see it there? I had the side cover off the pump while cranking and there wasn't any fuel running down.

Monday I'll go in search of some heavy wall tubing (while practicing social distancing) and make me an injector socket.

Hi Team,
until I can post pix again, fuel leakage past the Inj Pump Plungers still can be be minimal at the troughs in a worn Inj. Pump plunger and barrel--P & B.
Wear takes place by dirty fuel eroding the plunger at the helix and the barrel bore at the fuel bypass port.
There is a a possibility of excess leakage if the entire length of the bore and plunger are scored at a land that helps stop this occurring.

In the stop position, transfer pump pressure fuel can be seen as spurts as the plunger rises, due to restriction of the trapped fuel above the plunger exiting the bypass port and so creates a visible spurt when the injection line is loose or removed from the Inj. pump P & B Assembly.

Wasted half an hour trying to find where I posted pix in the past many times over from a Service Manual explaining all this clearly.

Cheers,
Eddie B.