No change in RPMs

[JazzDad]

I am trying to use the B-I-L's 1966 diesel Ford 3000. It worked fine last November.

Today it started right up, but moving the throttle makes no change in the engine speed. With the throttle pulled wide open, the engine runs at about 700 RPM (a guess, broken tach). If I move the throttle to idle, the engines slowly winds down until it dies. There is a hole (normally plugged) in the piping between the air filter and the intake manifold, probably drilled to allow ether injections. I pulled the plug to restart the engine, and it started after a long time of cranking. I went to plug the hole and checked the suction I was expecting to feel - air was blowing out of it. ( ? )

As said, it will start with a long crank time. If I put a load on it (mowing deck) it has only enough power to creep along in 2nd gear, and bogs down if it encounters just slightly thicker grass.

The throttle linkage seem to be all connected, and I can see a little half-moon shaped arm on the opposite side of the pump (?) where there are adjustable stops for idle and full throttle. The linkage travel is from stop to stop.

Exhaust cap opens straight up on start up, and I see no blockage in the air intake piping or filter.

Fuel was treated in November with Enzyme brand stabilizer (as it has been for some time).

Any thoughts?

 

[Jerry/MT]

I am trying to use the B-I-L's 1966 diesel Ford 3000. It worked fine last November.

Today it started right up, but moving the throttle makes no change in the engine speed. With the throttle pulled wide open, the engine runs at about 700 RPM (a guess, broken tach). If I move the throttle to idle, the engines slowly winds down until it dies. There is a hole (normally plugged) in the piping between the air filter and the intake manifold, probably drilled to allow ether injections. I pulled the plug to restart the engine, and it started after a long time of cranking. I went to plug the hole and checked the suction I was expecting to feel - air was blowing out of it. ( ? )

As said, it will start with a long crank time. If I put a load on it (mowing deck) it has only enough power to creep along in 2nd gear, and bogs down if it encounters just slightly thicker grass.

The throttle linkage seem to be all connected, and I can see a little half-moon shaped arm on the opposite side of the pump (?) where there are adjustable stops for idle and full throttle. The linkage travel is from stop to stop.

Exhaust cap opens straight up on start up, and I see no blockage in the air intake piping or filter.

Fuel was treated in November with Enzyme brand stabilizer (as it has been for some time).

Any thoughts?

A diesel does not use airflow to control the power like a spark ignition engine does with a throttle plate. The diesel controls power via fuel flow. On a diesel for a give rpm, the airflow is constant and as you increase load at constant rpm you increase fuel flow to increase power output. On a gasser, you throttle airflow through the carb throat which depresses the pressure in the venturi and the metering jet delivers more fuel to increase the power output with load and the max vacuum occurs at idle. Hence there is very little vacuum in the diesel intake manifold and it's a maximum at max airflow ( max rpm). That's why you diesel trucks have a vacuum pump for the power brake booster and spark ignition engine use manifold vacuum.

If your seeing high pressure in the intake manifold you most likely have a leaking valve. or the timing may be off.

Adding a biocide because of bacterial sludge in the fuel tank usually means that you also need to clean the tank outlet strainer/shutoff valve and possibly the tank itself. Fuel restriction will limit power output.

So check the fuel delivery from the tank outlet to the pump. Look for clogging at the tank outlet strainer, a pinched or dented fuel line, debris in the filter head passages, improperly installed O-ring in the filter assembly, etc.

 

[sd455dan]

Did the fuel shut off from the tank get screwed part way in , reducing fuel flow.

I know my 1967 3000 had a shut off in line but i always left it wide open.

I would also check the oil level in the Simms In-line injection pump- mine tended to get diluted with diesel after about 6 months of run time, might help to drain it and put fresh oil in it, It is possible the fuel rack is stuck and not moving.

 

[thepumpguysc]

Your either lacking sufficiant fuel to the pump or the rack is sticking INSIDE the inj. pump.
Remove the side cover on the pump & you should be able to reach in & move the control rack back & forth..
Pull the shut off cable & watch the rack move.. When was the last time the oil has been added OR changed !!???
The fill plug is the BIG one on top, the drain is the bottom plug & the FULL level plug is on the side of the pump..
Drain & full are 1/2" wrench.. I forget the size of the FILL plug but a couple of smacks w/ a hammer & an adjustable will get it loose.
That should take care of the problem.. Good luck & let us know how you make out.. TPG

 

[Kyle_in_Tex]

Good to hear from you jazz.

Sounds like good advice above. Hope you get it going.

 

[JazzDad]

Thank you for the replies. I won't be able to try anything until next weekend; the full-time job sees to that. And were are getting rain today! (So far this month we'd only gotten .4", and everything was drying out with the mid 90's temperatures already.)

When was the pump oil changed? Er, it left the factory in 1965...

 

[thepumpguysc]

1965??.. I SEE THAT on a daily basis, so don't feel bad.. all it takes is money to fix.. lol
OR a pint of transmission fluid & mineral spirits, if times are tight.. let it sit a week & spin the engine to distribute several times aweek, pulling & pushing the stop cable.. to free things up.. DO NOT RUN THE ENGINE WITH IT IN THERE..
THEN drain & refill w/ engine oil to the proper level.. once or twice..
DONT ask me how I know this.. {I stayed at a Holiday Inn lastnite, lol}

 

[JazzDad]

I'd like to throw out some more things I have done, to see if y'all still think it is the injector pump.

Trying easy stuff first: I was thinking low fuel flow. I took the line off after the lift pump. Cranking the engine produced about a tablespoon a second, which I assume was good. I reattached it, and took the line off after the fuel filters. The same amount came out (so I figure I didn't have clogged filters).

That, of course, caused the lines to bleed, and I had to get the air out up to the injectors. Once done, the engine started again. The throttle response is really slow, and only comes up to maybe 900 RPM. About 1/2 throttle produces idle speed, and if I close the throttle more, the engine winds down and dies. I can also force the engine off at any time by pulling the 'stop' lever.

The tractor must have the Simms system, as it looks like this photo.



Is the side cover the one behind the breather vent?

Please tell me if I should try draining the pump and putting in ATF to free it up.

 

[thepumpguysc]

The breather is attached to the side cover.. take off the 2, 1/2" screws & pry the cover off.. I'll bet it looks like baby poop in there. Lol
Just move the control rack back & forth.. spray your favorite cleaner inside & drain the oil/mess from the bottom screw..
Keep doing that until its clean.. THEN fill w/ ATF & actetone & let it sit a week..

 

[JazzDad]

Thank you for all of the responses.

I took the drain plug out of the injection pump. What ran out looked, and smelled, like what would be in the gas tank of a car sitting in a junk yard for 40 years. It was a very thin oil, and stunk bad. I took the side cover off and found the breather to be all clogged up. Cleaned it. Pushed the rack back and forth - it didn't seem to be hung up. I then observed this is the part that is moved by the stop lever. (I expected it to move with the throttle control.) So, not seeing anything obvious, I did what PumpGuy said (or as closely as I could). I put a pint of acetone, and because I didn't have the ATF that I thought I had on the shelf, I topped it off with 5W-40 motor oil. I was going to turn it over a few times, but forgot to pull the stop lever. I hit the key and it roared to life. Encouraged, I pulled the throttle and it quickly revved to full speed. I pushed it back to the idle position, and it IDLED. It didn't die!

I ran it about 10 minutes. Throttle response was quick and smooth. Next time I go over to the B-I-L's house, I will drain the pump and put the straight oil (per the manual) in it, unless you recommend anything else.

So, a big THANK YOU to PumpGuy! 30 years of working on pumps, I guess you have seen it all.