my 87 w150 has a 360 engine and a mechanical fuel pump . the engine has no emissions so i got only the one line from the tank hooked up to it the other 2 lines are caped . when i shut the motor off the fuel flows back out of the carb. and the glass filter, it not leaking any where so whats the problem ? i already changed the pump thinking the old one was bad . could it be put in wrong is there a backflow preventer missing , i'm lost
Speed Dragon
04-03-2008, 08:46 PM
I think that may be normal, mine does the same. You can put a one way check valve in the line to prevent it though. Even if the fuel in the line runs back down, the carb bowl is still full, so as long as the pump works properly it's not really a problem.
mikehopkinsjr
04-03-2008, 10:04 PM
Yea only takes like 1 good crank to get the line back up to speed
Delray Dude
04-04-2008, 07:58 AM
The flow back is a normal product of the fuel pump - especially after it has seen some duty - the one way plungers "seal" when the pressure is put on them - usually when the engine is running, but has to allow for some "slippage" due to the carb bowl beeing "full" and won't accept more fuel - otherwise you would have continual build up of pressure in the fuel line until something "bad" happens.
As much as the glass filters look good - I'd recommend not using one - if in the right (wrong) position - something could crack and be bad results.... NHRA tracks will throw you out if they see one.
