AC D17 Diesel Injector Pump Issue

Hey all,

First I would like to say this is a pretty great forum, and thanks.

I'm having trouble starting a D17, a 1950's model I believe.

I cleaned out the fuel valve underneath the tank and am getting good fuel flow up to the injector pump. However when cranking I do not get any flow from the pump to the heads. I've opened the bolts on the outflow side of the pump, to check for flow, without any luck. I usually crank in 10-15 second intervals.

Do you guys have any suggestions as what other things to check for before chalking it up to a rebuild?

Attached are some pictures.

https://imgur.com/a/XGz4nLS

Thanks for any help!

t-man

Do you have the fuel shut off control knob pulled to the rear (run) position? Has the control rod come unhooked from the shut off lever on the pump? Have you tried loosening the injector lines at the injectors and leaving them loose while cranking?

Most older AC tractors are bass akwards on the fuel stop control, out is run, in is fuel off. When did engine last run? If it's been more than six months there's a good chance internal valves and plungers are stuck inside. I've been repairing lots more pumps like that lately, either due to water/rust in fuel, OR the save the planet Bio diesel...

I forgot to mention, I did have the throttle lever pulled back. It's been over two months since it was run last. Are there any other ways to get that pump primed before pulling it? Thanks for the reply!

Yeh I had the shut off pulled to the rear. The control rod is attached to the lever; I'm pretty sure of it, but Ill double check. Yeh I
loosened a couple of the lines at the heads. There seemed to be some residual diesel in one of the lines but she wouldn't smoke.

Not sure exactly what's going on here, but your next best move is to throw a chain around the front axle and PULL START it. This will get the engine and injection pump spinning fast enough it should eventually start. If after a couple of miles it doesn't start, pull the pump. Have the D-17 in road gear and get the engine spinning above 1,000 RPM by your tachometer.

Once when I had one that just would not prime I bought this little inline diesel pump on Amazon that I plumbed in and just connected to the battery with alligator clips. Got it running, took the pump back off and went on down the road.

Hey DrAllis,

So I pulled the tractor about a half mile
in 4th gear. I wasn't able to get her
started yet but there was fuel up by the
cylinder heads. Does that mean the injector
pump indeed does work? Thanks again! Sorry
for the delayed reply by the way!

T

Do you get exhaust smoke with the injector lines tight? If you get smoke, then pump is opening injectors. No smoke means pump has problems.

Hey DieselTech,

No smoke unfortunately. When I disconnected the fuel lines after the injector after pulling it in gear for a bit there was fuel, but when I cranked it, I still did not see any diesel being pumped. Is that pretty much bad news for the pump? Thanks!

T

Pump may have stuck parts inside, or worse, hydraulic head is seized and drive shaft broken if the timing plate inside the pump does not turn as engine turns also.

Thanks for the help guys! Pump ended up being the problem. One more question do you guys know where I could get more of those washers for the banjo bolts?

The pump number I have is 4514812. Would this be interchangeable with other AC pump models

Such as: 4514022, Roosa Master, DBGFC637-32AJ, for example? Thanks!

The AC D17 used one of four pumps, DBGFC 637 12 AJ, 14AJ, 17AJ, or 32AJ being the latest pump. All should interchange, BUT if you're getting a used salvage yard pump it MAY have stuck parts inside too from setting. Maybe the pump you have can be repaired. I just repaired and returned an AC 180 pump that came in with stuck internal parts, but it's now working fine after a complete tear down and cleaning. I also have some banjo washers on hand too. The E-mail is [email protected] if you want to get in contact.

I am having the same problem as you. D17 series 2 diesel. Not run for about 15 years. I was told that it was parked because of an injector or pump problem. I cleaned the tank and lines. Replaced the filters and cleaned inlet screen in the injector pump transfer pump. Transfer pump vanes look very good. Everything was clean inside the transfer pump. Put in new fuel and pressurized it until I got fuel to the pump. Cranked and cranked to no success. Pump wouldn't pee a drop with the lines cracked loose on the pump. I want to take the pump to a rebuilder and have it looked at. He told me that the engine should be at 16 degrees btdc and the timing marks lined up in the pump inspection window when removing the pump. Where are the marks to tell me that the engine is at 16 degrees btdc? Thanks in advance.

There are no timing "marks" on those old Buda style engines. There is a headless bolt/pin attached to the engine back plate that you remove and turn around and re-insert it back into the hole while slowly turning the engine over. When the pin falls into a special timing hole in the flywheel, you are timed. The marks inside the inj pump window will now either be aligned OR be 180 degrees off, which then means you turn the engine over one more full revolution and then the inj pump marks are lined up. Trust me on this. The engine used to run. It probably ran just fine. It was in "time" then. It is still in time now. Timing doesn't change itself. If you remove the inj pump for repairs, first scribe a mark on the pump mounting flange to the engines front plate so you KNOW exactly where the inj pump was positioned at. These pumps can be rotated back and forth a few degrees in slotted mounting holes. MARK IT so you KNOW where it currently is. When you pull off the inj pump (after wiring the throttle lever fully open first) you will notice the drive shaft is a flat tang. On one side on the end of that flat drive tang there is a "dot". Look inside the inj pump and you will see another "dot". All you need to do when reinstalling the inj pump is align dot to dot and then when finishing up the pump mounting nuts, rotate the pump body back to the mark that you scribed and you are 100% right back to where it was before you took the pump off. It really is that easy. You really don't even need to use the timing pin or turn the engine over to align the pump window marks. Just remember dot to dot and scribe a mark on the mounting flange before inj pump removal.

Thanks for the great info. Yes, the tractor did run but not well when it was parked. Near as I can tell and remember the engine has never been worked on in it's entire long hard life. This tractor was bought new by my grandfather and then changed hands down to my uncle when he bought the farm. This thing did all the hard work for probably 30 years, plowing, discing, chopping, baling, cutting hay, grinding feed, loader work, hauling manure, plowing snow. It did it all. So I am really surprised it seems to be in as good condition as it is. As far as the timing of the pump: The rebuilder clued me in on the slotted holes. Good to know before removing it. Thanks for the info on the dots. Also good to know. I assume that means the pump would be 180 out if you didn't realign the dots. I'll see if I can get it off after the holidays celebrations are over. Merry Christmas dinner later today! So maybe Friday after work or Saturday.

No flat tang left on the end of the shaft coming from the gear housing. Kind of like a worn stub that would never drive anything. Looks the same inside the pump. Now what? Apparantly I will need a new drive shaft. And a new shaft inside the pump, hopefully not a new pump.