Join Date: Feb 2002
Location: Aaaahhhuuuuppp The Pub
Carb motor-EFI fuel pump
Once again I call on the help of the people at FF.
Can someone who knows stuff about running carby fed motors with EFI fuel pumps and not the old mechanical pump help me?
At the moment my setup consists of the standard XB fuel tank, EFI fuel pump, feeding upto a XF Weber carb, motor is an EFI 4ltr out of an EB but running the carb NOT efi.
Is there anything missing in this setup? I dont really want the hassle of a surge tank, but do I need a return line for fuel from the carby back to the tank? Is this possible to rig up on an XF Weber? Do I need to run a fuel pressure regualtor?
I find that Im having trouble starting the car in the mornings and even when it has warmed up. The symptoms are that the car turns over but wont start. Then after a while of frigging about with the accelerator it kind of "choofs" shit back up the carby. Sometimes I see smoke waft out from the air filter! I have also found the air filter holder base (sports filter, that chrome bit) has sometimes had fuel sitting in it, like seriously pooling in it. I have found one way to start the ute is to switch off the fuel pump (by flicking the kill switch) and then once it starts switching it back on.
WHATS GOING ON???
Another thing I have noticed the ute doing is when I back off while driving (irrespective of the revs) I get a lot of small backfiring. Its not a bang just more of a pop/rumble.
I have a theory (could be way off track) that the EFI pump is pushing too much fuel into the carb and is flooding it at start up. Then as Im driving it is still doing it when I back off and dont need as much fuel as when Im accelerating. But I thought that when the float is full the inlet for the fuel would get cut off.
Any ideas guys? Anyone with a carby/electronic fuel pump setup that can explain their system to me?
THE ONLY SUBSTITUTE FOR CUBIC INCHES IS FORCED INDUCTION