673 Wont Start

[bigrigpardo]

thanks thad i got some good advice from your post

but here is the next question. i was at the truck today and still couldnt figure why it wasnt getting fuel. when i opened the governor cover it seemed like the run stop cable hooked on to a lever in there. i moved the lever as far forward as it was set to go, but still wasnt able to gat fuel out of the injectors. i did notice that the number 1 injector is stuck in the up position. how do i get it down. how do u remove the injectors. how do you get this truck to run. i am going crazy i have been at this truck for like a year and havent gotten very far. i really wanted to go to macungie and barrys show but am never going to make it at this rate. what should i do now

andrew

[HK Trucking]

thanks thad i got some good advice from your post

but here is the next question. i was at the truck today and still couldnt figure why it wasnt getting fuel. when i opened the governor cover it seemed like the run stop cable hooked on to a lever in there. i moved the lever as far forward as it was set to go, but still wasnt able to gat fuel out of the injectors. i did notice that the number 1 injector is stuck in the up position. how do i get it down. how do u remove the injectors. how do you get this truck to run. i am going crazy i have been at this truck for like a year and havent gotten very far. i really wanted to go to macungie and barrys show but am never going to make it at this rate. what should i do now

andrew

Rob answered this question in your previous thread, so did Glenn Akers, and so did I:

Rob said:

Thad, you more than likely have a plunger,(one or more) stuck up in their respective bore(s) from sitting. The pump camshaft is turning but the stuck plunger will not let the rack turn the barrels allowing fuel. When the engine stop cable is pulled, the rack is pulled to the no fuel position where it probably is now.

The pump requires positive pressure to the fuel gallery that is supplied by the transfer pump. Since you have checked the filter housing and return line from the pump gallery, the only thing left is the high pressure side which is not getting fuel internally.

Take the pump off of the engine, remove the side cover and look for a stuck plunger. the innards look like a cam, and lifter setup for the engine. When the stuck item is located, there will be a space between the cam lobe, and the lifter. You will be able to see the valve spring compressed when it should not be. I usually soak the whole pump in a tub of diesel fuel for a bit and then pry, or force the stuck lifter back down. Once it, or they pop loose, reinstall onto engine and you should have a little better luck.

Glenn said:

If you take the top off of the governor you can feel the rack and it should move in and out . If it will not move it has to have the barrels and plungers re worked. If it will not move freely you dont whant to start because if could overspeed and kill you. If it moves the plungers lifers could still be stuck up but with the dry fuel we have now it is a thing that we see more ever day .If you have to buy a pump i have one off of a running engine.

HK said:

I've gotten those unstuck before without removing the pump.

Take off the side cover and the governor cover and soak everything real good with PB Blaster.

Make sure the stop control is in the run position.

Carefully tap on the rack linkage at the governor with a small hammer & drift, also you can tap on the bottom of the plungers toward the direction of full throttle.

After an hour or 2 of messing around with it, the rack & pungers will usually loosen up.

Keep spraying blaster on all the parts & keep working the rack back & forth by hand until it moves freely.

Before replacing the covers and attempting to start the engine, pull the engine stop to the stopped position and be sure the rack returns to the no fuel position. This step is important or you could have a runaway if the stop control does not pull the rack closed.

[bigrigpardo]

Rob answered this question in your previous thread, so did Glenn Akers, and so did I:

Rob said:

Glenn said:

HK said:

see i read all of this before. i took the governor cover off and the lever for the rack was stiff. i got it to move in and out good enough to get it to the fuel position. i then cranked the motor with the number three injector opened and nothing came out. i dont think that one stuck plunger would keep the entire motor from getting fuel so theres were my next hunt starts. i want to remove the six injectors and clean them and the injector block in hopes that the only problem was excess build up . so with that how do u remove the injectors. do they un screw with a wrench or is there another way. cause as u all probably read we put fuel in the bowl for the filter cause the tanks are all crapped up. we r getting fuel to the rack but not through the injectors. the truck runs on starting fluid but no fuel so i cant have it running for more than 20 seconds

now what

[HK Trucking]

That's all it takes is 1 stuck plunger to jam up the entire rack.

All 6 plungers have teeth which engage with the rack, which is controlled by the governor.

If one plunger ain't moving it is impossible for the rack to move, hence the other 5 plungers ain't gonna open up either.

[bigrigpardo]

That's all it takes is 1 stuck plunger to jam up the entire rack.

All 6 plungers have teeth which engage with the rack, which is controlled by the governor.

If one plunger ain't moving it is impossible for the rack to move, hence the other 5 plungers ain't gonna open up either.

is there any way to get the plunger down without removing the rack. and still do u know how to remove the injectors. Also another question while it was running on starter fluid i couldnt rev up the motor any thought why it just idled

[HK Trucking]

Now, if you indeed do have the rack moving all 6 plungers as it should, crack the high pressure fuel lines at the injectors and crank the engine with the throttle open. this will purge the air out of the high pressure lines, and you will be able to tell if you're getting fuel to that point.

If fuel squirts out of the loosened high pressure lines, tighten them up again and the engine should start.

2 years ago I got one running that had been sitting for 12 years, rack was completely jammed up, but with a little help it started up without pulling any injectors out.

[bigrigpardo]

Now, if you indeed do have the rack moving all 6 plungers as it should, crack the high pressure fuel lines at the injectors and crank the engine with the throttle open. this will purge the air out of the high pressure lines, and you will be able to tell if you're getting fuel to that point.

If fuel squirts out of the loosened high pressure lines, tighten them up again and the engine should start.

2 years ago I got one running that had been sitting for 12 years, rack was completely jammed up, but with a little help it started up without pulling any injectors out.

1. i opened the governor cover and there was a lever in there that went back and forth is that the fuel shut off.

2. if i move it and it moves t the fuel position then why wouldnt the fuel be getting to the other 5 cylinders

[Rob]

1. i opened the governor cover and there was a lever in there that went back and forth is that the fuel shut off.

2. if i move it and it moves t the fuel position then why wouldnt the fuel be getting to the other 5 cylinders

You probably have stuck plungers. You will have to remove the side cover of the pump (opposite the block side) to check.

Go to the library and look at a book with a diagram. It is very easy to figure out with a photo of what is internal to the pump, and what we are talking about.

Rob

[HK Trucking]

1. i opened the governor cover and there was a lever in there that went back and forth is that the fuel shut off.

The part that moves when you move the stop control (where the stop cable attaches to the governor) is the "fuel shut off", it pulls the rack back to the "no fuel" position when you pull the engine stop control.

2. if i move it and it moves t the fuel position then why wouldnt the fuel be getting to the other 5 cylinders

The fact that the stop control is moving inside the governor doesn't mean that the rack is moving.

The rack is the part that is connected to the governor and runs all the way along the inside of the pump next to the plungers. The rack has teeth on it that engage with the teeth on the plungers and when the rack moves toward the front of the pump this turns the plungers to increase the amount of fuel delivered to the injectors, or if the rack moves to the rear it decreases the amount of fuel.

When the stop control is pulled it pulls the rack all the way to the rear, preventing the plungers from sending any fuel to the injectors, thereby stopping the engine.

As I said before, since the rack teeth are engaged with all 6 plungers, if even 1 plunger can't turn, then the rack can't move and none of the plungers can turn.

I personally enjoy solving these kind of problems, and if I was closer to your area I'd be there helping right now, but 1000 miles is a bit far.

[bigrigpardo]

to all out there my number 1 plunger is stuck and my stop fuel lever is stiff if the stop fuel lever is the lever under the governor cap then i am right and i did have it in the right position but how can only one plunger keep fuel out of the other five injectors.

[bigrigpardo]

thanks hk i guess that is kinda far but if the lever under the governor cap moves all the way forwrd then shouldnt the rack move to. i mean if the rack was stuck then theoretically the lever shouldnt move at all right???

[theakerstwo]

If that engine does start with a stuck rack you may have a runaway and it could kill you. I have seen a mack run so fasthat it brock a fan blade and it when thru the hood not more 4 ft behind a mechanic that was running away from it.

if you are lucky enough to get it free enough to start you may not get it to stay free and if you are ready to meat the load then think along time before you try to start it the next time. when one runs away that means you cant stop it.

[bigrigpardo]

i get it i am gonna give it anothe rtry next week and will let all of you know were i get. i hope i get it running

[HK Trucking]

OK, heres another way to tell if the rack & plungers are moving:

Take off that cover on the side of the inj. pump (the big cover, if I remember right it's held on by about a half dozen bolts with 1/2 inch heads) then look in there while you move the stop control from stop to run.

The plungers should be turning when you do this, if not then something is stuck, and you can refer to the original thread for methods to free it up.

[bigrigpardo]

OK, heres another way to tell if the rack & plungers are moving:

Take off that cover on the side of the inj. pump (the big cover, if I remember right it's held on by about a half dozen bolts with 1/2 inch heads) then look in there while you move the stop control from stop to run.

The plungers should be turning when you do this, if not then something is stuck, and you can refer to the original thread for methods to free it up.

now were getting somewere.

what should be spinning the springs or what???????????

[HK Trucking]

now were getting somewere.

what should be spinning the springs or what???????????

Yes, the springs and the toothed parts on the plungers

Not spinning, but rotating about 90 degrees or so from shut off to full throttle.

(With the engine off @zero RPM, the governor will put the rack to full fuel as soon as the stop control moves to the run position if everything is free in there)