Running out of fuel in a diesel

I have a small diesel tractor that I think I ran out of fuel :smack: . I have heard some horror stories about running a diesel dry. Mostly, about needing to prime the fuel pump.

If that’s true, why? Gas cars are fuel injected, and they don’t have this problem.

Anyone else hear about this?

And in case you’re wondering, I can’t get it started. Gonna try again today.

Fuel injected gas cars have a different type of pump, an electric inline pump that doesn’t need to be primed like the engine driven pump on a diesel. Don’t think running out of fuel won’t cause a problem though The electric pumps are cooled and lubricated by fuel so running them dry can destroy it or shorten its life.

I have heard of this as well, but never encountered it being an actual problem. I would think it would depend on where the pump is located, the type of pump it is, and the temperature (viscosity) of the fuel.


My line of work is highway construction, and I’m surrounded daily by diesel-powered equipment. When a machine runs out of fuel, my day usually begins to suck pretty quickly.

Fuel-injected cars have fuel pumps in or near their fuel tanks to feed the fuel (typically gasoline) to their engines. Diesel equipment generally does not.

Your diesel engine probably has two pumps – a main fuel pump and an injector pump. Both are likely mechanical pumps located on the engine. The difficulty level of priming the pumps, once dry, can vary dramatically. Some main pumps have a manual priming lever, some don’t. If yours has one, try that first. If it doesn’t, you’ll probably have to resort to loosening the injector lines to allow the system to purge itself of air past the injector pump. In extreme cases, we’ve had to loosen the lines at the injectors.

Good luck, and watch that fuel guage!

To add a bit both diesel and gas engines may be fuel injected but they aren’t the same. Gas engines inject just over the intake valve, ouside the cylinder or in some case back at the throttle body of the maifold. Diesel injects fuel directly into the combustion chamber during compression so requires much higher pressures neccessitating a positive displacement pump.

My John Deere Diesel tractor has a self bleeding fuel system! Ha Ha!

Yeah, my tractor has a warning light when the fuel gets low. I try not to depend on it. I usually only let the tank get about half empty.

Yesterday, when I discovered I was out of fuel, I went to the shed to grab my fuel can to go into town to get more. The can was full. Last time I bought fuel, I forgot to put it in. Warning light must be broken too.


Why dosn’t the air just get pumped into the cylinders?

Gonna be a fun day. I have had a heat lamp on the fuel pump all night, It’s currently -1 degree F.

Thanks for your responses everyone.

O.K. I understand the reason better now. I always knew that diesel injected into the cylinder. Didn’t know it was on compression. So that’s the need for ‘direct drive, high pressure’.

Oh boy, it’s up to 2 degrees F now, gonna go get my sandles and shorts. :smiley:

is gonna…

I sympathize with you. Not too long ago I had to change a starter while lying on my back under the car which was located on a frozen ice/gravel dirveway. It was probably 10 degrees though, so I had it much better than you.:wink:

Bingo, thanks TBone.

I loosend the injector lines at the injector and cranked away untill they leaked some fuel.

It’s not running yet (too cold) but it’s smoking like the devil. I’ve got fuel. I’m letting the starter rest, and charging the battery.

Thanks again, now that I have a tractor again, I guess I have work to do.

whuckfistle - yeah, it sure can be a bitch. But it feels great when you get it done.

Only on the Dope.