Home Forums Hunting & Shooting Hunter's Campfire Diesel mechanics? Help me out

Here’s the deal: Allis chalmers 6060 4 cylinder diesel. Fuel tank is above engine, gravity fed no tank fuel pump. I ran it out of fuel by accident - no problem filled it up, bled the fuel lines and filter all the way to the injector pump and it started a little rough, smoothed out and ran for 10 minutes fine. Then it slowly lost power and RPM’s and stalled out. From then on it starts and runs briefly before idling down and stalling on its own. The longer it sits the longer it will run before idling down and out. OK… starving for fuel so I checked and cleaned every line and fitting from the tank through the filter and to the injector pump including the bleed fitting at the injector pump and a new fuel filter. No change - it will start, rev up to full throttle, then slowly RPM down until it stalls. The longer you let it sit in between the longer it will run at high RPM before idling down to a stall - but only up to a few minutes max. I don’t know much about injector pumps, but maybe air in there and it’s not priming correctly?

You might want to change the filter as whatever debris that was in the tank and lines might be obstructing the fuel flow. So while it may be air it might also be debris in the filter

Sounds like feul line obstruction. My tractor did that once and a wasp had gotten in a feul line

Most likely there is a return line from the injectors to the fuel tank and it is plugged.

There's always crud in the bottom a tank. If you run out of fuel, you'll be sucking the crud off the bottom and that will clog a filter. Clean or replace it.

Might have a screen somewhere.

Check your tank vent too.

and check the tank outlet too , with it running out , some trash may have settled in there

I don't know schidt about ag equipment, but if you have a 433T engine, they are notorious for flex ring failure plugging the return line. They used the 433T on Koehring log loaders. After you have double checked EVERYTHING to do with fuel flow... I'd bet flex ring failure is where your problem lies.

If you’re sure the supply lines aren’t plugged, these two guys right here beat me to my suggestion. This is a common issue on the 100 series Allis’, I don’t know anything about the 60 series.

Thanks guys, been through the lines, outlet, filter etc. several times looking for blockages and crud. Already tried the tank vent. Will try the return line next!

Two links, same issues, all say clean supply lines, then look at return line like mentioned above.

https://www.allischalmers.com/forum/ran-6060-out-of-fuel-i-think_topic152887.html

Injection Pump Ed on this link is a pump guru

https://www.allischalmers.com/forum/1981-allis-6080-surging-issues_topic138190.html

Also, if that's a 433T, it may have a Roosa Master wannabe injection pump made by Stanadyne. They fail frequently enough that every fuel injection shop in the US can re-do them for cheap, about 10 years ago, they were only 550 bucks your pump, 650 exchange with your good core. Now listen up...if you pull the pump yourself, learn how to time that sonofabitch before you take it off. Over and out.

Try bleeding fuel lines all the way to injectors

Break a fuel line close to your injector pump. Wrap an airhose/blow gun with a rag and put some pressure in your fuel tank thru the fuel cap. If you cannot get fuel to flow out where you broke the line you have and obstruction. If that is the case blow backwards thru your fuel lines until it seems to clear.

You are tired of hearing from me, another thing, (knowing nothing about ag applications) every Roosa Master/Stanadyne I ever worked on has the fuel transfer pump in the housing on the far end opposite the drive end...and there is a FUEL INLET SCREEN in the end fitting, as insurance against filter failure. Take a look at it before going further. The long sitting period/ better revs makes me think it is related. Do not try to run the engine too much until you find a problem, the high pressure plungers will score and possibly seize, they depend on a generous flow of fuel for lubrication and cooling.

The crud in the filter is not visible.


Are you sure that there is no fuel pump as gravity feeding would not run a constant pressure not to mention that it may be illegal. The pump may be inside the tank and may have it's own partially clogged filter

I don’t know 60 series, but the generation before that was purely gravity without question.

Meaning no lift pump? Shirley there is an injector pump?

Gravity flow to the injector pump (as stated in the OP) Our buddy Dusty is saying it’s illegal and impossible to not have a fuel pump such as in the tank which couldn’t be further from the truth.

And don’t call me Shirley. 🤣🤣

I’ve never banged a Shirley