Air in fuel

G

GEARJAMMER1SC

ALWAYS TINKERING
Joined
Dec 2, 2009
Messages
14
I have been fighting a shudder shake for a year now. I am running a new mech. lift pump (second new one) and I have replaced all the lines and fittings with new ones. Also pulling fuel through a Haisley machine draw staw. I cursed the first new lift pump after hookin a line from it to a container of fuel eliminating the tank and supply line and still seeing air in the return line from the p-pump. New lift pump and same problem. I then eliminated the factory 24v fuel filter and replaced it with a dual filter 20micron and 2micron with all new push loc fittings and still air in fuel. Has anyone had trouble running the mech lift pump on their conversion or am I the lucky one!!:doh:
 
GEARJAMMER1SC said:
I have been fighting a shudder shake for a year now. I am running a new mech. lift pump (second new one) and I have replaced all the lines and fittings with new ones. Also pulling fuel through a Haisley machine draw staw. I cursed the first new lift pump after hookin a line from it to a container of fuel eliminating the tank and supply line and still seeing air in the return line from the p-pump. New lift pump and same problem. I then eliminated the factory 24v fuel filter and replaced it with a dual filter 20micron and 2micron with all new push loc fittings and still air in fuel. Has anyone had trouble running the mech lift pump on their conversion or am I the lucky one!!:doh:
Click to expand...

I've been running one on my conversion for 5 or 6 years. No problems.
 
The fuel is being agitated by the pump. Nothing you can do about it unless you put an air seperating unit on it.
 
Have seen injectors nozzles not sealing good blow the cylinder pressure back thru the injector into the pump making the fuel very agitated.
 
Put completely rebuilt injectors back in and same problem. Pulled mechanical lift pump and replaced with a FASS 150 and checked the return line. No air at idle and runs alot better at idle. Bring RPMs up and it starts the shake at around 1500 and air in return line coming out injection pump. Changed to stock injectors with lowered popoffs and no change. Also checked timing with a light and she sits still idling at 18*. As you bring up RPM it advances and retards so bad you can't get a reading. Tried a stock p-pump and still the same. Enough to make a preacher cuss!
 
Single feed. Wonder if it could be something with the head. I am grasping for straws now.
 
You must log in or register to reply here.
Back
Top