Hooley needs a little help with a fuel pump

[Hooley]

A friend has put a 454 in a 74 that has been a diesel engine. The fuel pump has 3 places for hoses. The fuel inlet , the outlet to the carb and a smaller out let that leakes fuel when the engine is running.  Can we plug this line off and not cause any problems?  I ran this engine on the run in stand and it worked fine. We now have a problem of not wanting to idle.  I didn't know if this was part of the idle problem.

Thank you
 Hooley

[wayne petty]

yes.. you can plug the smallest outlet on the mechanical fuel pump without problems..

that is a return feed to keep the gasoline flowing to reduce the chance of VAPORLOCK..  where the fuel absorbs enough heat to boil in the pump cavity. in the lines to the carb or in the line from the tank..

the small hose allows constant circulation..  back to the tank...

there are fuel pumps without the return line..  depending on the outlet angle.. and height..


plugging off the return line should NOT effect fuel pressure at the carb..

is there any chance that the fuel lines in the chassis are filled with dirt or rust..

have you don't a full flow test yet???   extending the disconnected line at the carb into a clean clear 2 or 3 liter plastic soda bottle..   somebody cranks the engine for 10 to 15 seconds.. while you watch the pulses of fuel from the end of the hose into the bottle..

each should be even in volume ..  not diminishing as the fuel pump cavity is emptied..

please use a magnet of the fuel in the bottle.. to see if there is any Red dUST in it..

[Hooley]

Wayne,
          You have once again saved my bacon. That is what we wanted to know. Since I made the first post we found a vacuum leak under the carb.  

   So once again all is well in Chelsea, OK

 Hooley