i have a 1985 250sd 4x4 4sp and it starts like a dream runs for 10 sec and then quits.hold it to the floor and spin it over for about 20 sec it fire up and runs perfect all day (OR TILL IT COOLS DOWN AGAIN) at a loss and thinking of a big fire .....any ideas would be helpful thanks

 

found it leaky injector letting air in to system on the return line