7.3 idi help

[corliss010492]

i have a 94 7.3 idi non turbo, it doesnt run. it sat for like three months. i can fill the fuel filter up and crank it over and it will run but once it burns the fuel out of the fuel filter it dies and the fuel filter is low on fuel, im thinking it just has air in the lines between the filter and tank but im not sure, either that or its the pump, any ides, thanks

 

[IDIDieselJohn]

Could be a dead mechanical fuel pump.


While cranking, open the tire valve on the filter head, that should **** out alot of fuel.

 

[DragRag]

Replace the mechanical lift pump most likely.

 

[gunz]

Replace the mechanical lift pump most likely.

Sounds about right to me.

 

[Compu Doc]

How much fuel is in the tank?. Make sure that you at least have half a tank. Besides the other suggestion of a bad mechanical lift pump it could also be the pickup tube in the tank. If you don't have at least half a tank of fuel than I would put enough in that you do to start. If you have at least half a tank than replace the lift pump.

 

[icanfixall]

All the above postings are correct. these trucks have a poor fuel tank pickup foot on the in tanks suction lines. They will break off and you can't suck out the last 1/4 tank of fuel. So you pull air into the fuel system. Easy fix if thats the issue. Do as posted and vent the filter housing when cranking. Post back what you find.

 

[corliss010492]

there is about a half a tank of fuel in the truck. and when you open the valve on the fuel filter housing fuel comes out but not much and it kinda burps out a little then stops and more comes out

 

[redneckaggie]

if it burps, stops, then burps again I would vote to fill the tank you are on all the way up and try to crank again and see if that helps if it does then the pickup tube in the tank is broken

 

[rhkcommander]

Try taking the fuel cap off the tank. If the wrong one is used the tank will pull a vacuum. I had a full tank and the same symptoms until I popped em off.

If both tanks have a problem then it's lift pump or a clog or something else

 

[icanfixall]

Sure sounds like your sucking air from somewhere. You need at least 1/2 tank of fuel to pull from. No amount of 1/4 in either tank will draw up if the pickups are broken off. So you have two tanks with 1/4 in each.. Any other planet thats fine. But our fords need more than 1/4 tank of fuel to draw from. If you remove the fuel supply line from the mechanical lift pump and crank the engine you will have a better idea of fuel flow. Be careful and catch what pumps out. No need to make a mess....

 

[biggin92]

When i occasionally encounter something like this, i pressurize my tank alittle to send fuel to the filter head to get it started, and if it doesnt stay running then replace the lift pump.

 

[corliss010492]

thanks for all the help guys, im going to replace the lift pump and fill it up and hopefully that will fix the problem