I just bought an 89 f250 7.3 idi diesel 5 speed manual 4x4. I was driving home with a load of hog feed and all of sudden I started to lose power. It felt like I would have only half the power as I would push the petal all the way down and then all of a sudden full power would kick in and run fine. This happened multiple times in about a 5 minute time frame. Then, the engine started to chug as I had the petal half-way down and then full power would eventually kick in. This chugging got worse and worse until eventually it chugged constantly and then finally the engine cut out and I pulled over. It wouldn't start after that. Though it will turn over, it just won't start. I obviously had to get towed home. I disconnected the fuel line before and after the water/fuel seperator and I had fuel flowing through those lines. I disconnected the injector line at one of the injectors and just a little bit of fuel was spitting out of that line when I would turn the engine over. Is that little sputter normal or should it be a straight stream of fuel flowing through the injectors while turning the engine over?

 

This sounds like you're running out of fuel. Did you happen to have 1/4 tank left? The sucker end in the tank is made of rubber and tends to disintegrate after this many years.

The little bit from the IP is normal

 

My fuel gauge isn't working too well, but I believe I probably was around 1/4 tank left in fuel. Thank you. I will put some fuel in and see if that helps. If it starts then I bet your right about the sucker end. If fuel was shooting out of the fuel line when I disconnected it, then do you still think that it would be that sucker end? When you say sucker end do you mean the end of the fuel pump that is inside the fuel tank?

 

The fuel pump on our trucks is on the side of the engine. All there is in the tank is just a piece of steel line with a rubber cone and filter on the end. Fuel gets sucked through that up to the low-pressure fuel pump on the side of the engine, and then from there through the filter and into the IP.

Chances are, you are right about the 1/4 mark. What happens is that if you are at any angle, the fuel will go to one side of the tank and you will suck air. Usually not so much of a problem due to the filter end being right at the bottom.

Until you fix that tank, I'd not drive it under 3/8 of a tank to be safe. Also, if you can, use both tanks so you've got a backup. I alternate between them myself.

In addition, I tend to use my trip counter to tell me how many miles of fuel I have left in my current tank. When I switch tanks, I zero the trip counter.

 

So I put some fuel in the tank today and it still won't start. Do you have another suggestion? Thank you.

 

Fuel will come out of the line when disconnected but connected, the air compresses and the injector will not open. If you ran it dry, it could take some cranking to get fuel back tot the ip.

As a secondary precaution, I replaced all my rubber fuel lines because some lines, at the curves or bends, had flattened out somewhat, reducing the interior dimension, and my thoughts were that the line might be reducing even more when hot and under max draw/throttle.

 

Make sure when cranking you have it floored. It increases the fuel flow and helps priming.

 

Does it run off the OTHER tank?

 

Thank you all so much for your help. I took your recommendation on slamming the gas pedal the whole time while trying to start and it finally started chugging and then all of a sudden it started up. She purrs like a kitten now. Your were right in that I obviously ran it dry and it had air in there that needed expelled before fuel would start flowing. Thank you, thank you, thank you so much. The other tank is not in use for some reason so I need to look into what that reason is. Also, I obviously need to fix the fuel gauge. I assume the needle is inconsistent due to the float sensor in the tank. So that will
Be my next project. Is there a way to test to see if the issue is with the gauge in the dash vs. the float in the tank with out having to drop the tank first.

Thanks again for all of your help.