I have been having some shifting issues so today at work i disconnected my batteries and turned the key back on at lunch time. I forgot about it and didn't get back to it for about 3 hours. turned the key off reconnected batteries turned key on pushed pedal to the floor let it up slowly started the truck idle was a bit loapy then it smoothed up. pulled out of the driveway and noticed when i stepped on it my low fp light came on. which comes on at 5lbs. it wasnt on constant so i nursed it home. i have a stock carter lp from cummins on the truck the ff looks clean but i have a new one im going to put in as well as another new lp. the thing is now i cant make the light come on now matter how hard im on it. just making sure there is nothing to do with the apps reset before i go tearing into this thing again.sorry for the long post. Thanks in advance

 

The fuel pressure still needs to be known.
If you have an old R12 Freon install kit w/gauge, you can use it to check the lift pump fuel pressure, otherwise kits are avalable at most chain type auto parts stores.

Don't forget to close the fill valve.





Screw the connector on the fitting of the injector pump on the driver's side of the engine.
Turn the keyswitch just enough to "bump" the starter to get The Free 25 Second Lift Pump Run.



Stock spec is 10psi+, most folks look for 15psi.

 

got a fass on the way thanks to lary it will be here sat. tks