I have a 1991 f250 diesel. It runs great but starts up poorly when it sits for more than a day. :eek: I found some cracked return lines and replaced them. If it sits for more than a day or two it will try to start, run a few seconds and then shut down. After that it takes five or six (or more) starts to get going. This is causing wear and tear on the starter and concerns me. It does start up in hot or cold areas and the glow plugs check out. :) I think trapped air, fuel injector or injector pump are possible causes. Any ideas:confused:

I have a 1991 f250 diesel. It runs great but starts up poorly when it sits for more than a day. :eek: I found some cracked return lines and replaced them. If it sits for more than a day or two it will try to start, run a few seconds and then shut down. After that it takes five or six (or more) starts to get going. This is causing wear and tear on the starter and concerns me. It does start up in hot or cold areas and the glow plugs check out. :) I think trapped air, fuel injector or injector pump are possible causes. Any ideas:confused:
Is this the 7.3 diesel?they have a fuel transfer pump very similar to an automotive type--check the tranfer pressure--if it is not to spec it will be hard starting.

See if this could be part of your problem.

In cold weather this year, many diesel owners have had problems with the new ultralow-sulfur fuel. The problem comes during the refining process used to attain the ultralow-sulfur ratio. That affects the naturally occurring wax in diesel in such a way that it can cause the fuel to turn from liquid to gel more readily in cold temperatures. Gelled fuel clogs the fuel filters and starves the engine, causing it to stop. Diesel fuel additives, such as Amsoil's, and ultraclean kerosene added to the fuel help prevent this problem.