Hi Guys,
How bad would it be if I ran out of fuel in my 91 with the 5.9 cummins turbo Diesel plow truck pickup? The fuel gauge doesn't work and not sure dipping the tank would help. Does anyone know what the common causes are for fuel gauge failure?
I know: just fix the gauge!
Thanks

 

How bad you ask? I guess that depends on how much you value your time. A 1st timer could waste several hours to most of the day re priming all the fuel lines to the motor.

Wiring issues [check grounds, missing plugs] is the most likely culprit.

 

At least the Cummins has a manual priming lever on the lift pump.

The contact/resistance strip on the sender can get fouled or worn too.

 

Carry a 17mm wrench with you to loosen the injector nuts and the bleeder bolt. Keep a couple gallons of fuel in the bed until you get the problem figured out.

 

Actually it's not that bad if you have the proper tools. First you add fuel of course. Then you open the little valve at the outlet of the fuel filter and work the priming lever until fuel comes out oif that vent. Then you loosen the banjo at the return line outlet on the VE pump. Then you loosen all six of the lines at the injectors. Crank the engine until you get fuel spurting out of all six injectors then tighten them down. It should then start up and run rough for a few minutes until it works the remaining air out of the lines. Takes about 20 minutes for me but I'm getting slow.

Edwin

 

Fwiw, I've changed injectors and fuel filters without much more than pumping the lever. May take 2 tries @ 5 seconds cranking each. Starts a little stumbly and with a little throttle clears in under a minute. YMMV.

 

He wasn't asking about changing filters. He was asking about running it out of fuel. I can only assume dead in the road style outta fuel.

If you have no fuel from your engine to the fuel tank 15 FT away, it is going to take longer than 2 pumps of the LP and a couple of minutes.

Just fill up the tank and keep track of mileage, after 300 miles or so, fill it back up.
This will work until you can fix the issue.

 

When my gauge went bad, it was the sending unit in the tank. Soon as I replaced the sending unit, it's been good ever since.

Since the tank holds 30 gallons, my gauge when it bottoms out on empty, still has 6 to 7 gallons left in it. Since your gauge doesn't work, playing it safe would be the way to go as Ollie stated already. Fill it to the brim, reset your trip meter in the cab, and drive it till you hit 300 or so. You'll have further than this depending on your actual fuel mileage, which in my truck averages 15 to 17MPG, whether I'm on a long highway drive, keeping it at 65mph, or crusing around town This means I wouldn't run out of fuel until 450 miles on the trip meter, give or take.

Having an Auto vs Stick makes a big difference, as some fellas here with a standard shift are getting closer to 20mpg. You can put a fuel additive in it which can sometimes provide you a 1 mpg increase in fuel mileage, as the better the truck runs, the less your foot pushes to the floor. I use Howes Diesel treat every tank, and it seems to make the truck run smoother, and better fuel economy, depending on the time of year, and whether or not they're pushing their "winter fuel" here in hell.

Now if you're a "Cowboy rolling coal", like my wife likes to say, then your mileage will be way different than mine, so only you will know.

There is a company in new York State that repairs the fuel sending units. I sent mine up there, and it's been perfect ever since. My commercial diesel Fuso fuel sending unit went bad, and they fixed me up good. Samantha and Daniel are really good peoples.

Tri-Starr Radiator – Your Fuel Sending Unit Specialist (tristarrradiator.com)